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Records |
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Author |
Delville, R.; Malard, B.; Pilch, J.; Schryvers, D. |
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Title |
Microstructure changes during non-conventional heat treatment of thin NiTi wires by pulsed electric current studied by transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
58 |
Issue |
13 |
Pages |
4503-4515 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Transmission electron microscopy, electrical resistivity measurements and mechanical testing were employed to investigate the evolution of microstructure and functional superelastic properties of 0.1 mm diameter as-drawn NiTi wires subjected to a non-conventional heat treatment by controlled electric pulse currents. This method enables a better control of the recovery and recrystallization processes taking place during the heat treatment and accordingly a better control on the final microstructure. Using a stepwise approach of millisecond pulse annealing, it is shown how the microstructure evolves from a severely deformed state with no functional properties to an optimal nanograined microstructure (2050 nm) that is partially recovered through polygonization and partially recrystallized and that has the best functional properties. Such a microstructure is highly resistant against dislocation slip upon cycling, while microstructures annealed for longer times and showing mostly recrystallized grains were prone to dislocation slip, particularly as the grain size exceeds 200 nm. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000279787100020 |
Publication Date |
2010-06-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
110 |
Open Access |
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Notes |
Multimat; FWO
IAA |
Approved |
Most recent IF: 5.301; 2010 IF: 3.791 |
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Call Number |
UA @ lucian @ c:irua:83279 |
Serial |
2062 |
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Permanent link to this record |
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Author |
Bartova, B.; Wiese, N.; Schryvers, D.; Chapman, J.N.; Ignacova, S. |
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Title |
Microstructure of precipitates and magnetic domain structure in an annealed Co38Ni33Al29 shape memory alloy |
Type |
A1 Journal article |
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Year |
2008 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
56 |
Issue |
16 |
Pages |
4470-4476 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The microstructure of a Co38Ni33Al29 ferromagnetic shape memory alloy was determined by conventional transmission electron microscopy (TEM), electron diffraction studies together with advanced microscopy techniques and in situ Lorentz microscopy. Rod-like precipitates, 1060 nm long, of hexagonal close-packed -Co were confirmed to be present by high-resolution TEM. The orientation relationship between the precipitates and B2 matrix is described by the Burgers orientation relationship. The crystal structure of the martensite obtained after cooling is tetragonal L10 with a (111) twinning plane. The magnetic domain structure was determined during an in situ cooling experiment using the Fresnel mode of Lorentz microscopy. While transformation proceeds from B2 austenite to L10 martensite, new domains are nucleated, leading to a decrease in domain width, with the magnetization lying predominantly along a single direction. It was possible to completely describe the relationship between magnetic domains and crystallographic directions in the austenite phase though complications existed for the martensite phase. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000259931300033 |
Publication Date |
2008-06-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
23 |
Open Access |
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Notes |
Multimat |
Approved |
Most recent IF: 5.301; 2008 IF: 3.729 |
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Call Number |
UA @ lucian @ c:irua:72321 |
Serial |
2072 |
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Permanent link to this record |
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Author |
Boullay, P.; Schryvers, D.; Ball, J.M. |
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Title |
Nano-structures at martensite macrotwin interfaces in Ni65Al35 |
Type |
A1 Journal article |
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Year |
2003 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
51 |
Issue |
5 |
Pages |
1421-1436 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The atomic configurations at macrotwin interfaces between microtwinned martensite plates in Ni65Al35 material are investigated using transmission electron microscopy. The observed structures are interpreted in view of possible formation mechanisms for these interfaces. A distinction is made between cases in which the microtwins, originating from mutually perpendicular {110} austenite planes, enclose a final angle larger or smaller than 90degrees. Two different configurations, a crossing and a step type are described. Depending on the actual case, tapering, bending and tip splitting of the smaller microtwinvariants are observed. The most reproducible deformations occur in a region of approximately 5-10 nm width around the interface while a variety of structural defects are observed further away from the interface. These structures and deformations are interpreted in terms of the coalescence of two separately nucleated microtwinned martensite plates and the need to accommodate remaining stresses. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000181677700018 |
Publication Date |
2003-03-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
31 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.301; 2003 IF: 3.059 |
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Call Number |
UA @ lucian @ c:irua:48364 |
Serial |
2248 |
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Permanent link to this record |
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Author |
Potapov, P.L.; Ochin, P.; Pons, J.; Schryvers, D. |
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Title |
Nanoscale inhomogeneities in melt-spun Ni-Al |
Type |
A1 Journal article |
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Year |
2000 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
48 |
Issue |
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Pages |
3833-3845 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000089632800003 |
Publication Date |
2002-07-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
28 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.301; 2000 IF: 2.166 |
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Call Number |
UA @ lucian @ c:irua:48362 |
Serial |
2265 |
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Permanent link to this record |
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Author |
Idrissi, H.; Renard, K.; Ryelandt, L.; Schryvers, D.; Jacques, P.J. |
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Title |
On the mechanism of twin formation in FeMnC TWIP steels |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
58 |
Issue |
7 |
Pages |
2464-2476 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Although it is well known that FeMnC TWIP steels exhibit high work-hardening rates, the elementary twinning mechanisms controlling the plastic deformation of these steels have still not been characterized. The aim of the present study is to analyse the extended defects related to the twinning occurrence using transmission electron microscopy. Based on these observations, the very early stage of twin nucleation can be attributed to the pole mechanism with deviation proposed by Cohen and Weertman or to the model of Miura, Takamura and Narita, while the twin growth is controlled by the pole mechanism proposed by Venables. High densities of sessile Frank dislocations are observed within the twins at the early stage of deformation, which can affect the growth and the stability of the twins, but also the strength of these twins and their interactions with the gliding dislocations present in the matrix. This experimental evidence is discussed and compared to recent results in order to relate the defects analysis to the macroscopic behaviour of this category of material. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000276523200018 |
Publication Date |
2010-01-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
244 |
Open Access |
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Notes |
Iap |
Approved |
Most recent IF: 5.301; 2010 IF: 3.791 |
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Call Number |
UA @ lucian @ c:irua:82270 |
Serial |
2441 |
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Permanent link to this record |
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Author |
Tirry, W.; Schryvers, D. |
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Title |
Quantitative determination of strain fields around Ni4Ti3 precipitates in NiTi |
Type |
A1 Journal article |
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Year |
2005 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
53 |
Issue |
4 |
Pages |
1041-1049 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000226774500014 |
Publication Date |
2004-12-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
97 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.301; 2005 IF: 3.430 |
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Call Number |
UA @ lucian @ c:irua:55686 |
Serial |
2750 |
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Permanent link to this record |
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Author |
Cao, S.; Nishida, M.; Schryvers, D. |
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Title |
Quantitative three-dimensional analysis of Ni4Ti3 precipitate morphology and distribution in polycrystalline Ni-Ti |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
59 |
Issue |
4 |
Pages |
1780-1789 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The three-dimensional size, morphology and distribution of Ni4Ti3 precipitates in a Ni50.8Ti49.2 polycrystalline shape memory alloy with a heterogeneous microstructure have been investigated using a focused ion beam/scanning electron microscopy slice-and-view procedure. The mean volume, central plane diameter, thickness, aspect ratio and sphericity of the precipitates in the grain interior as well as near to the grain boundary were measured and/or calculated. The morphology of the precipitates was quantified by determining the equivalent ellipsoids with the same moments of inertia and classified according to the Zingg scheme. Also, the pair distribution functions describing the three-dimensional distributions were obtained from the coordinates of the precipitate mass centres. Based on this new data it is suggested that the existence of the heterogeneous microstructure could be due to a very small concentration gradient in the grains of the homogenized material and that the resulting multistage martensitic transformation originates in strain effects related to the size of the precipitates and scale differences of the available B2 matrix in between the precipitates. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000287265100045 |
Publication Date |
2010-12-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
34 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 5.301; 2011 IF: 3.755 |
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Call Number |
UA @ lucian @ c:irua:85533 |
Serial |
2766 |
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Permanent link to this record |
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Author |
Shi, H.; Frenzel, J.; Martinez, G.T.; Van Rompaey, S.; Bakulin, A.; Kulkova, A.; Van Aert, S.; Schryvers, D. |
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Title |
Site occupation of Nb atoms in ternary Ni-Ti-Nb shape memory alloys |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
74 |
Issue |
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Pages |
85-95 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Nb occupancy in the austenite B2-NiTi matrix and Ti2Ni phase in NiTiNb shape memory alloys was investigated by aberration-corrected scanning transmission electron microscopy and precession electron diffraction. In both cases, Nb atoms were found to prefer to occupy the Ti rather than Ni sites. A projector augmented wave method within density functional theory was used to calculate the atomic and electronic structures of the austenitic B2-NiTi matrix phase and the Ti2Ni precipitates both with and without addition of Nb. The obtained formation energies and analysis of structural and electronic characteristics explain the preference for Ti sites for Nb over Ni sites. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000338621400009 |
Publication Date |
2014-05-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
21 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.301; 2014 IF: 4.465 |
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Call Number |
UA @ lucian @ c:irua:118334 |
Serial |
3028 |
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Permanent link to this record |
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Author |
Seo, J.W.; Schryvers, D. |
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Title |
TEM investigation of the microstructure and defects of CuZr martensite: 1: morphology and twin systems |
Type |
A1 Journal article |
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Year |
1998 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
46 |
Issue |
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Pages |
1165-1175 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000072289100009 |
Publication Date |
2002-07-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
46 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.301; 1998 IF: 1.834 |
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Call Number |
UA @ lucian @ c:irua:48360 |
Serial |
3479 |
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Permanent link to this record |
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Author |
Seo, J.W.; Schryvers, D. |
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Title |
TEM investigation of the microstructure and defects of CuZr martensite: 2: planar defects |
Type |
A1 Journal article |
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Year |
1998 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
46 |
Issue |
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Pages |
1177-1183 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000072289100010 |
Publication Date |
2002-07-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
21 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.301; 1998 IF: 1.834 |
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Call Number |
UA @ lucian @ c:irua:48361 |
Serial |
3480 |
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Permanent link to this record |
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Author |
Chen, X.; Cao, S.; Ikeda, T.; Srivastava, V.; Snyder, G.J.; Schryvers, D.; James, R.D. |
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Title |
A weak compatibility condition for precipitation with application to the microstructure of PbTe-Sb2Te3 thermoelectrics |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
59 |
Issue |
15 |
Pages |
6124-6132 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
We propose a weak condition of compatibility between phases applicable to cases exhibiting full or partial coherence and Widmanstätten microstructure. The condition is applied to the study of Sb2Te3 precipitates in a PbTe matrix in a thermoelectric alloy. The weak condition of compatibility predicts elongated precipitates lying on a cone determined by a transformation stretch tensor. Comparison of this cone with the long directions of precipitates determined by a slice-and-view method of scanning electron microscopy combined with focused ion beam sectioning shows good agreement between theory and experiment. A further study of the morphology of precipitates by the Eshelby method suggests that interfacial energy also plays a role and gives an approximate value of interfacial energy per unit area of 250 dyn cm−1. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000294086900026 |
Publication Date |
2011-07-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
8 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.301; 2011 IF: 3.755 |
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Call Number |
UA @ lucian @ c:irua:92388 |
Serial |
3911 |
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Permanent link to this record |
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Author |
Amin-Ahmadi, B.; Connétable, D.; Fivel, M.; Tanguy, D.; Delmelle, R.; Turner, S.; Malet, L.; Godet, S.; Pardoen, T.; Proost, J.; Schryvers, D.; Idrissi, H. |
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Title |
Dislocation/hydrogen interaction mechanisms in hydrided nanocrystalline palladium films |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
111 |
Issue |
111 |
Pages |
253-261 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The nanoscale plasticity mechanisms activated during hydriding cycles in sputtered nanocrystalline Pd films have been investigated ex-situ using advanced transmission electron microscopy techniques. The internal stress developing within the films during hydriding has been monitored in-situ. Results showed that in Pd films hydrided to β-phase, local plasticity was mainly controlled by dislocation activity in spite of the small grain size. Changes of the grain size distribution and the crystallographic texture have not been observed. In contrast, significant microstructural changes were not observed in Pd films hydrided to α-phase. Moreover, the effect of hydrogen loading on the nature and density of dislocations has been investigated using aberration-corrected TEM. Surprisingly, a high density of shear type stacking faults has been observed after dehydriding, indicating a significant effect of hydrogen on the nucleation energy barriers of Shockley partial dislocations. Ab-initio calculations of the effect of hydrogen on the intrinsic stable and unstable stacking fault energies of palladium confirm the experimental observations. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000375812100027 |
Publication Date |
2016-04-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
14 |
Open Access |
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Notes |
This work was carried out in the framework of the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs, under Contract No. P7/21. The support of the FWO research project G012012N “Understanding nanocrystalline mechanical behaviour from structural investigations” for B. Amin-Ahmadi is also gratefully acknowledged. This work was granted access to the HPC resources of CALMIP (CICT Toulouse, France) under the allocations 2014-p0912 and 2014-p0749. |
Approved |
Most recent IF: 5.301 |
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Call Number |
c:irua:132678 |
Serial |
4054 |
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Permanent link to this record |
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Author |
van der Rest, A.; Idrissi, H.; Henry, F.; Favache, A.; Schryvers, D.; Proost, J.; Raskin, J.-P.; Van Overmeere, Q.; Pardoen, T. |
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Title |
Mechanical behavior of ultrathin sputter deposited porous amorphous Al2O3 films |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
|
Volume |
125 |
Issue |
125 |
Pages |
27-37 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The determination of the mechanical properties of porous amorphous Al2O3 thin films is essential to address reliability issues in wear-resistant, optical and electronic coating applications. Testing the mechanical properties of Al2O3 films thinner than 200 nm is challenging, and the link between the mechanical behavior and the microstructure of such films is largely unknown. Herein, we report on the elastic and viscoplastic mechanical properties of amorphous Al2O3 thin films synthesized by reactive magnetron sputtering using a combination of internal stress, nanoindentation, and on-chip uniaxial tensile testing, together with mechanical homogenization models to separate the effect of porosity from intrinsic variations of the response of the sound material. The porosity is made of voids with 2e30 nm diameter. The Young's modulus and hardness of the films decrease by a factor of two when the deposition pressure increases from 1.2 to 8 mTorr. The contribution of porosity was found to be small, and a change in the atomic structure of the amorphous Al2O3 matrix is hypothesized to be the main contributing factor. The activation volume associated to the viscoplastic deformation mechanism is around 100 Å3. Differences in the atomic structure of the films could not be revealed by electron diffraction, pointing to a minute effect of atomic arrangement on the elastic properties. |
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Place of Publication |
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Editor |
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Language |
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Wos |
000394201500003 |
Publication Date |
2016-12-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
5 |
Open Access |
OpenAccess |
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Notes |
This work has been funded by the Belgian Science Policy through the IAP 7/21 project. The support of the ‘Fonds Belge pour la Recherche dans l’Industrie et l’Agriculture (FRIA)’ for A.v.d.R. is also gratefully acknowledged, as well as the support of FNRS through the grant PDR T.0122.13 “Mecano”. |
Approved |
Most recent IF: 5.301 |
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Call Number |
EMAT @ emat @ c:irua:138990 |
Serial |
4330 |
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Permanent link to this record |
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Author |
Ghidelli, M.; Idrissi, H.; Gravier, S.; Blandin, J.-J.; Raskin, J.-P.; Schryvers, D.; Pardoen, T. |
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Title |
Homogeneous flow and size dependent mechanical behavior in highly ductile Zr 65 Ni 35 metallic glass films |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
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Volume |
131 |
Issue |
131 |
Pages |
246-259 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Motivated by recent studies demonstrating a high strength – high ductility potential of nano-scale metallic glass samples, the mechanical response of freestanding Zr65Ni35 film with sub-micron thickness has been investigated by combining advanced on-chip tensile testing and electron microscopy. Large deformation up to 15% is found for specimen thicknesses below 500 nm with variations depending on specimen size and frame compliance. The deformation is homogenous until fracture, with no evidence of shear banding. The yield stress is doubled when decreasing the specimen cross-section, reaching ~3 GPa for small cross-sections. The fracture strain variation is related to both the stability of the test device and to the specimen size. The study concludes on clear disconnect between the mechanisms controlling the onset of plasticity and the fracture process. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000402343400023 |
Publication Date |
2017-03-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
42 |
Open Access |
OpenAccess |
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|
Notes |
This work has been funded by the Belgian Science Policy through the IAP 7/21 project. We acknowledge IDS-FunMat for the PhD financial support.We thank the Renatech network and the PTA (Plateforme Technologique Amont) in Grenoble (France) for TFMG deposition facilities. The WINFAB infrastructure at the UCL and the help of R. Vayrette and M. Coulombier for the on-chip tests. H. Idrissi is currently mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). |
Approved |
Most recent IF: 5.301 |
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Call Number |
EMAT @ emat @ c:irua:142642 |
Serial |
4562 |
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Permanent link to this record |
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Author |
Cautaerts, N.; Delville, R.; Stergar, E.; Schryvers, D.; Verwerft, M. |
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Title |
Characterization of (Ti,Mo,Cr)C nanoprecipitates in an austenitic stainless steel on the atomic scale |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
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Volume |
164 |
Issue |
|
Pages |
90-98 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Nanometer sized (Ti,Mo,Cr)C (MX-type) precipitates that grew in a 24% cold worked Ti-stabilized austenitic stainless steel (grade DIN 1.4970, member of the 15-15Ti austenitic stainless steels) after heat treatment were fully characterized with transmission electron microscopy (TEM), probe corrected high angle annular dark field scanning transmission electron microscopy (HR-HAADF STEM), and atom probe tomography (APT). The precipitates shared the cube-on-cube orientation with the matrix and were facetted on {111} planes, yielding octahedral and elongated octahedral shapes. The misfit dislocations were believed to have Burgers vectors a/6<112> which was verified by geometrical phase analysis (GPA) strain mapping of a matrix-precipitate interface. The dislocations were spaced five to seven atomic
planes apart, on average slightly wider than expected for the lattice parameters of steel and TiC. Quantitative atom probe tomography analysis of the precipitates showed that precipitates were significantly enriched in Mo, Cr and V, and that they were hypostoichiometric with respect to C. These findings were consistent with a reduced lattice parameter. The precipitates were found primarily on Shockley
partial dislocations originating from the original perfect dislocation network. These novel findings could contribute to the understanding of how TiC nanoprecipitates interact with point defects and matrix dislocations. This is essential for the application of these Ti-stabilized steels in high temperature environments or fast spectrum nuclear fission reactors. |
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Place of Publication |
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Language |
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Wos |
000456902800008 |
Publication Date |
2018-10-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
2 |
Open Access |
Not_Open_Access: Available from 12.10.2020
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Notes |
This work was supported by ENGIE [contract number 2015-AC- 007 e BSUEZ6900]; the U.S. Department of Energy, Office of Nuclear Energy under DOE Idaho Operations Office Contract DE-AC07- 051D14517 as part of a Nuclear Science User Facilities experiment; and by the MYRRHA program in development at SCKCEN, Belgium. Special thanks to Dr. H. Mezerji and Dr. T. Altantzis for the work on the FEI Titan microscope.We also want to thank Ms. J. Burns for the help on the FIB and Dr. Y. Wu at CAES for conducting the APT measurements. |
Approved |
Most recent IF: 5.301 |
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Call Number |
EMAT @ emat @c:irua:154873UA @ admin @ c:irua:154873 |
Serial |
5060 |
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Permanent link to this record |
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Author |
Ghidelli, M.; Orekhov, A.; Bassi, A.L.; Terraneo, G.; Djemia, P.; Abadias, G.; Nord, M.; Béché, A.; Gauquelin, N.; Verbeeck, J.; Raskin, J.-p.; Schryvers, D.; Pardoen, T.; Idrissi, H. |
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Title |
Novel class of nanostructured metallic glass films with superior and tunable mechanical properties |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Acta Materialia |
Abbreviated Journal |
Acta Mater |
|
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Volume |
|
Issue |
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Pages |
116955 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
A novel class of nanostructured Zr50Cu50 (%at.) metallic glass films with superior and tunable mechanical
properties is produced by pulsed laser deposition. The process can be controlled to synthetize a wide
range of film microstructures including dense fully amorphous, amorphous embedded with nanocrystals
and amorphous nano-granular. A unique dense self-assembled nano-laminated atomic arrangement
characterized by alternating Cu-rich and Zr/O-rich nanolayers with different local chemical enrichment
and amorphous or amorphous-crystalline composite nanostructure has been discovered, while
significant in-plane clustering is reported for films synthetized at high deposition pressures. This unique
nanoarchitecture is at the basis of superior mechanical properties including large hardness and elastic
modulus up to 10 and 140 GPa, respectively and outstanding total elongation to failure (>9%), leading to
excellent strength/ductility balance, which can be tuned by playing with the film architecture. These
results pave the way to the synthesis of novel class of engineered nanostructured metallic glass films
with high structural performances attractive for a number of applications in microelectronics and
coating industry. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Wos |
000670077800004 |
Publication Date |
2021-05-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
27 |
Open Access |
OpenAccess |
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Notes |
H.I. is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). This work was supported by the Fonds de la Recherche Scientifique – FNRS under Grant T.0178.19 and Grant CDR– J011320F. We acknowledge funding for the direct electron detector used in the 4D stem studies from the Hercules fund 'Direct electron detector for soft matter TEM' from the Flemish Government J.V acknowledges funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 823717 – ESTEEM3. A.O. has received partial funding from the GOA project “Solarpaint” of the University of Antwerp. A.B. and J.V. acknowledge funding through FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy') from the Flanders Research Fund. M.G. and A.L.B acknowledge Chantelle Ekanem for support in PLD depositions. |
Approved |
Most recent IF: 5.301 |
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Call Number |
EMAT @ emat @c:irua:178142 |
Serial |
6761 |
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Permanent link to this record |
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Author |
Yang, M.; Orekhov, A.; Hu, Z.-Y.; Feng, M.; Jin, S.; Sha, G.; Li, K.; Samaee, V.; Song, M.; Du, Y.; Van Tendeloo, G.; Schryvers, D. |
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Title |
Shearing and rotation of β'' and β' precipitates in an Al-Mg-Si alloy under tensile deformation : in-situ and ex-situ studies |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Acta Materialia |
Abbreviated Journal |
Acta Mater |
|
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Volume |
220 |
Issue |
|
Pages |
117310 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The interaction between dislocations and nano-precipitates during deformation directly influences hardening response of precipitation-strengthening metals such as Al-Mg-Si alloys. However, how coherent and semi-coherent nano-precipitates accommodate external deformation applied to an Al alloy remains to be elucidated. In-situ tensile experiments in a transmission electron microscope (TEM) were conducted to study the dynamic process of dislocations cutting through coherent needle-like beta '' precipitates with diameters of 3 similar to 8 nm. Comprehensive investigations using in-situ, ex-situ TEM and atom probe tomography uncovered that beta '' precipitates were firstly sheared into small fragments, and then the rotation of the fragments, via sliding along precipitate/matrix interfaces, destroyed their initially coherent interface with the Al matrix. In contrast, semi-coherent beta' precipitates with sizes similar to beta '' were more difficult to be fragmented and accumulation of dislocations at the interface increased interface misfit between beta' and the Al matrix. Consequently, beta' precipitates could basically maintain their needle-like shape after the tensile deformation. This research gains new insights into the interaction between nano-precipitates and dislocations. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
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Corporate Author |
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Place of Publication |
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Wos |
000705535300005 |
Publication Date |
2021-09-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 5.301 |
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Call Number |
UA @ admin @ c:irua:182528 |
Serial |
6884 |
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Permanent link to this record |
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Author |
Vanhumbeeck, J.-F.; Tian, H.; Schryvers, D.; Proost, J. |
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Title |
Stress-assisted crystallisation in anodic titania |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Corrosion science |
Abbreviated Journal |
Corros Sci |
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Volume |
53 |
Issue |
4 |
Pages |
1269-1277 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The relationship between the microstructural and internal stress evolution during Ti anodising is discussed. Samples anodised galvanostatically to 12 V and 40 V, corresponding to different stages of the internal stress evolution, were examined by in-plane and cross-section transmission electron microscopy. Electron diffraction patterns have been complemented with stoichiometry data obtained from energy loss near edge structure spectra. The sample anodised to 40 V was observed to consist of two regions, with a crystallised inner region adjacent to the metal/oxide interface. Crystallisation of this region is associated with the presence of large compressive internal stresses which build up during anodising up to 12 V. |
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Place of Publication |
Oxford |
Editor |
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Wos |
000288972000016 |
Publication Date |
2010-12-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0010-938X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.245 |
Times cited |
11 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 5.245; 2011 IF: 3.734 |
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Call Number |
UA @ lucian @ c:irua:88385 |
Serial |
3177 |
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Permanent link to this record |
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Author |
Gaouyat, L.; He, Z.; Colomer, J.-F.; Lambin, P.; Mirabella, F.; Schryvers, D.; Deparis, O. |
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Title |
Revealing the innermost nanostructure of sputtered NiCrOx solar absorber cermets |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Solar energy materials and solar cells |
Abbreviated Journal |
Sol Energ Mat Sol C |
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Volume |
122 |
Issue |
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Pages |
303-308 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Conversion of solar energy into thermal energy helps reducing consumption of non-renewable energies. Cermets (ceramicmetal composites) are versatile materials suitable, amongst other applications, for solar selective absorbers. Although the presence of metallic Ni particles in the dielectric matrix is a prerequisite for efficient solar selective absorption in NiCrOx cermets, no clear evidence of such particles is reported so far. By combining comprehensive chemical and structural analyses, we reveal the presumed nanostructure which is at the origin of the remarkable optical properties of this cermet material. Using sputtered NiCrOx layers in a solar absorber multilayer stack on aluminium substrate allows us to achieve solar absorptance as high as α=96.1% while keeping thermal emissivity as low as ε=2.2%, both values being comparable to best values recorded so far. With the nanostructure of sputtered NiCrOx cermets eventually revealed, further optimization of solar absorbers can be anticipated and technological exploitation of cermet materials in other applications can be foreseen. |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000331494200040 |
Publication Date |
2013-11-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0927-0248; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.784 |
Times cited |
12 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.784; 2014 IF: 5.337 |
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Call Number |
UA @ lucian @ c:irua:113086 |
Serial |
2902 |
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Permanent link to this record |
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Author |
Cao, S.; Zeng, C.Y.; Li, Y.Y.; Yao, X.; Ma, X.; Samaee, V.; Schryvers, D.; Zhang, X.P. |
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Title |
Quantitative FIB/SEM three-dimensional characterization of a unique Ni₄Ti₃ network in a porous Ni50.8Ti49.2 alloy undergoing a two-step martensitic transformation |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Materials Characterization |
Abbreviated Journal |
Mater Charact |
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Volume |
169 |
Issue |
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Pages |
110595 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The three-dimensional (3D) nanostructure of Ni4Ti3 precipitates in a porous Ni50.8Ti49.2 alloy has been re-constructed by “Slice-and-View” in a Focused Ion Beam/Scanning Electron Microscope (FIB/SEM). The 3D configuration of these precipitates forming a network structure in the B2 austenite matrix has been characterized via 3D visualization and quantitative analysis including volume fraction, skeleton, degree of anisotropy and local thickness. It is found that dense Ni4Ti3 precipitates occupy 54% of the volume in the B2 austenite matrix. Parallel Ni4Ti3 precipitates grow alongside the surface of a micro-pore, yielding an asymmetric structure, while nano voids do not seem to affect the growth of Ni4Ti3 precipitates. The small average local thickness of the precipitates around 60 nm allows their coherency with the matrix, and further induces the R-phase transformation in the matrix. On the other hand, the B2 matrix exhibits a winding and narrow structure with a skeleton of 18.20 mm and a thickness similar to the precipitates. This discontinuous matrix segmented by the Ni4Ti3 network and pores is responsible for the gradual transformation by stalling the martensite propagation. |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000584353100001 |
Publication Date |
2020-08-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1044-5803 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.7 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
; This work was supported by the National Natural Science Foundation of China under Grant Nos. 51401081 and 51571092, the Natural Science Foundation of Guangdong Province through Key Project under Grant No. 2018B0303110012 and General Project under Grant No. 2017A030313323, and China Scholarship Council (CSC). ; |
Approved |
Most recent IF: 4.7; 2020 IF: 2.714 |
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Call Number |
UA @ admin @ c:irua:173547 |
Serial |
6590 |
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Permanent link to this record |
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Author |
Ding, L.; Raskin, J.-P.; Lumbeeck, G.; Schryvers, D.; Idrissi, H. |
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Title |
TEM investigation of the role of the polycrystalline-silicon film/substrate interface in high quality radio frequency silicon substrates |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Materials Characterization |
Abbreviated Journal |
Mater Charact |
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Volume |
161 |
Issue |
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Pages |
110174-10 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The microstructural characteristics of two polycrystalline silicon (poly-Si) films with different electrical properties produced by low-pressure chemical vapour deposition on top of high resistivity silicon substrates were investigated by advanced transmission electron microscopy (TEM), including high resolution aberration corrected TEM and automated crystallographic orientation mapping in TEM. The results reveal that the nature of the poly-Si film/Si substrate interface is the main factor controlling the electrical resistivity of the poly-Si films. The high resistivity and high electrical linearity of poly-Si films are strongly promoted by the Sigma 3 twin type character of the poly-Si/Si substrate interface, leading to the generation of a huge amount of extended defects including stacking faults, Sigma 3 twin boundaries as well as Sigma 9 grain boundaries at this interface. Furthermore, a high density of interfacial dislocations has been observed at numerous common and more exotic grain boundaries deviating from their standard crystallographic planes. In contrast, poly-Si film/Si substrate interfaces with random character do not favour the formation of such complex patterns of defects, leading to poor electrical resistivity of the poly-Si film. This finding opens windows for the development of high resistivity silicon substrates for Radio Frequency (RF) integrated circuits (ICs) applications. |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000521515800027 |
Publication Date |
2020-01-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1044-5803 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.7 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
; H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). ; |
Approved |
Most recent IF: 4.7; 2020 IF: 2.714 |
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Call Number |
UA @ admin @ c:irua:168664 |
Serial |
6621 |
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Permanent link to this record |
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Author |
Yang, T.; Kong, Y.; Li, K.; Lu, Q.; Wang, Y.; Du, Y.; Schryvers, D. |
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Title |
Quasicrystalline clusters transformed from C14-MgZn₂ nanoprecipitates in Al alloys |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Materials characterization |
Abbreviated Journal |
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Volume |
199 |
Issue |
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Pages |
112772-112777 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Ultrafine faulty C14-MgZn2 Laves phase precipitates containing quasicrystalline clusters and demonstrating the formation of binary quasicrystalline precipitates with Penrose-like random-tiling were observed in the over-aged FCC matrix of a commercial 7N01 Al-Zn-Mg alloy, using high angle annular dark field scanning transmission electron microscopy. The evolution from C14-Laves phase to quasicrystalline clusters is illustrated, and five-fold symmetry can be found in both real and reciprocal spaces. Our findings reveal the possibility of quasicrystalline formation from Laves phase in a highly plastic metal matrix like Al and demonstrate the structural relationship between Laves phase and quasicrystals. |
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Editor |
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Wos |
000954788800001 |
Publication Date |
2023-03-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1044-5803 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.7 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 4.7; 2023 IF: 2.714 |
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Call Number |
UA @ admin @ c:irua:196106 |
Serial |
8446 |
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Permanent link to this record |
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Author |
Radi, A.; Khalil-Allafi, J.; Etminanfar, M.R.; Pourbabak, S.; Schryvers, D.; Amin-Ahmadi, B. |
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Title |
Influence of stress aging process on variants of nano-N4Ti3precipitates and martensitic transformation temperatures in NiTi shape memory alloy |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Materials & design |
Abbreviated Journal |
Mater Design |
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Volume |
262 |
Issue |
262 |
Pages |
74-81 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In this study, the effect of a stress aging process on the microstructure and martensitic phase transformation of NiTi shape memory alloy has been investigated. NiTi samples were aged at 450 degrees C for 1 h and 5 h under different levels of external tensile stress of 15, 60 and 150 MPa. Transmission electron microscopy (TEM) was used to characterize different variants and morphology of precipitates. The results show that application of all stress levels restricts the formation of precipitates variants in the microstructure after I h stress aging process. However, all variants can be detected by prolonging aging time to 5 h at 15 MPa stress level and the variants formation is again restricted by increasing the stress level. Moreover, the stress aging process resulted in changing the shape of precipitates in comparison with that of the stress-free aged samples. Coffee-bean shaped morphologies were detected for precipitates in all stress levels. According to the Differential Scanning Calorimetry (DSC) results, the martensite start temperature (M-s) on cooling shifts to higher temperatures with increasing the tensile stress during the aging process. This can be related to the change ofaustenite to martensite interface energy due to the different volume fractions and variants of precipitates. (c) 2018 Elsevier Ltd. All rights reserved. |
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Place of Publication |
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Editor |
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Wos |
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Publication Date |
2018-01-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0264-1275 |
ISBN |
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Additional Links |
UA library record; ; WoS full record; WoS citing articles |
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Impact Factor |
4.364 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 4.364 |
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Call Number |
UA @ lucian @ c:irua:149854 |
Serial |
4938 |
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Permanent link to this record |
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Author |
Miotti Bettanini, A.; Ding, L.; Mithieux, J.-D.; Parrens, C.; Idrissi, H.; Schryvers, D.; Delannay, L.; Pardoen, T.; Jacques, P.J. |
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Title |
Influence of M23C6 dissolution on the kinetics of ferrite to austenite transformation in Fe-11Cr-0.06C stainless steel |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Materials & design |
Abbreviated Journal |
Mater Design |
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Volume |
162 |
Issue |
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Pages |
362-374 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The design of high-strength martensitic stainless steels requires an accurate control over the stability of undesired phases, like carbides and ferrite, which can hamper strength and ductility. Here, the ferrite to austenite transformation in Fe-11Cr-0.06C has been studied with a combined experimental-modelling approach. Experimental observations of the austenization process indicate that austenite growth proceeds in multiple steps, each one characterized by a different transformation rate. DICTRA based modelling reveals that the dissolution of the M23C6 Cr-rich carbides leads to Cr partitioning between austenite and parent phases, which controls the rate of transformation through (i) a soft-impingement effect and (ii) consequent stabilization of the ferrite, which remains untransformed inside chromium-enriched-zones even after prolonged austenization stage. Slow heating rate and smaller initial particle sizes allow the design of ferrite-free microstructure. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000454128400036 |
Publication Date |
2018-12-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0264-1275 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.364 |
Times cited |
3 |
Open Access |
OpenAccess |
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Notes |
The authors thank Professor Anne-Francoise Gourgues-Lorenzon and Helene Godin, Ecole Nationale Superiore des Mines de Paris (MINES ParisTech) for their fruitful discussions. AMB thanks Stijn Van den broek (Universiteit Antwerpen) for the skillful preparation of TEM samples with FIB. The financial support of CBMM (Companhia Brasileira de Metalurgia e Mineracao) is gratefully acknowledged. L. Delannay is mandated by the FNRS-Belgium. Computational resources have been provided by the supercomputing facilities of the UCLouvain (CISM/UCL) and the Consortium des Equipements de Calcul Intensif en Federation Wallonie Bruxelles (CÉCI) funded by the Fond de la Recherche Scientifique de Belgique (F.R.S.-FNRS) under convention 2.5020.11.; Cbmm; F.r.s.-fnrs, 2.5020.11 ; |
Approved |
Most recent IF: 4.364 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:156721 |
Serial |
5161 |
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Permanent link to this record |
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Author |
Montero-Sistiaga, M.L.; Pourbabak, S.; Van Humbeeck, J.; Schryvers, D.; Vanmeensel, K. |
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Title |
Microstructure and mechanical properties of Hastelloy X produced by HP-SLM (high power selective laser melting) |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Materials & design |
Abbreviated Journal |
Mater Design |
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Volume |
165 |
Issue |
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Pages |
107598 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In order to increase the production rate during selective laser melting (SLM), a high power laser with a large beam diameter is used to build fully dense Hastelloy X parts. Compared to SLM with a low power and small diameter beam, the productivity was increased from 6 mm3/s to 16 mm3/s, i.e. 2.6 times faster. Besides the productivity benefit, the influence of the use of a high power laser on the rapid solidification microstructure and concomitant material properties is highlighted. The current paper compares the microstructure and tensile properties of Hastelloy X built with low and high power lasers. The use of a high power laser results in wider and shallower melt pools inducing an enhanced morphological and crystallographic texture along the building direction (BD). In addition, the increased heat input results in coarser sub-grains or high density dislocation walls for samples processed with a high power laser. Additionally, the influence of hot isostatic pressing (HIP) as a post-processing technique was evaluated. After HIP, the tensile fracture strain increased as compared to the strain in the as-built state and helped in obtaining competitive mechanical properties as compared to conventionally processed Hastelloy X parts. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000458259300020 |
Publication Date |
2019-01-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0264-1275 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.364 |
Times cited |
15 |
Open Access |
OpenAccess |
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Notes |
This research was supported by the ENGIE Research and Technology Division. The authors acknowledge ENGIE Research and Technology Division for the use of the SLM280HL machine. S.P. likes to thank the Flemish Science Foundation FWO for financial support under Project G.0366.15N. |
Approved |
Most recent IF: 4.364 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:157469 |
Serial |
5176 |
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Permanent link to this record |
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Author |
Samaee, V.; Gatti, R.; Devincre, B.; Pardoen, T.; Schryvers, D.; Idrissi, H. |
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Title |
Dislocation driven nanosample plasticity: new insights from quantitative in-situ TEM tensile testing |
Type |
A1 Journal Article |
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Year |
2018 |
Publication |
Scientific Reports |
Abbreviated Journal |
Sci Rep-Uk |
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Volume |
8 |
Issue |
1 |
Pages |
12012 |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
Intrinsic dislocation mechanisms in the vicinity of free surfaces of an almost FIB damage-free single crystal Ni sample have been quantitatively investigated owing to a novel sample preparation method combining twin-jet electro-polishing, in-situ TEM heating and FIB. The results reveal that the small-scale plasticity is mainly controlled by the conversion of few tangled dislocations, still present after heating, into stable single arm sources (SASs) as well as by the successive operation of these sources. Strain hardening resulting from the operation of an individual SAS is reported and attributed to the decrease of the length of the source. Moreover, the impact of the shortening of the dislocation source on the intermittent plastic flow, characteristic of SASs, is discussed. These findings provide essential information for the understanding of the regime of ‘dislocation source’ controlled plasticity and the related mechanical size effect. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000460200900001 |
Publication Date |
2018-08-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.259 |
Times cited |
9 |
Open Access |
Not_Open_Access |
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Notes |
Financial support from the Flemish (FWO) and German Research Foundation (DFG) through the European M-ERA.NET project “FaSS” (Fatigue Simulation near Surfaces) under the grant numbers GA.014.13 N and SCHW855/5-1, respectively, is gratefully acknowledged. V. Samaee also acknowledges the FWO research project G012012N “Understanding nanocrystalline mechanical behaviour from structural investigations”. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). Dr. Ruth Schwaiger is acknowledged for providing the Ni foils used to prepare the in-situ TEM tensile specimens. |
Approved |
Most recent IF: 4.259 |
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Call Number |
EMAT @ emat @c:irua:155772 |
Serial |
5136 |
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Permanent link to this record |
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Author |
Idrissi, H.; Ghidelli, M.; Béché, A.; Turner, S.; Gravier, S.; Blandin, J.-J.; Raskin, J.-P.; Schryvers, D.; Pardoen, T. |
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Title |
Atomic-scale viscoplasticity mechanisms revealed in high ductility metallic glass films |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
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Volume |
9 |
Issue |
1 |
Pages |
13426 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The fundamental plasticity mechanisms in thin freestanding Zr65Ni35 metallic glass films are investigated in order to unravel the origin of an outstanding strength/ductility balance. The deformation process is homogenous until fracture with no evidence of catastrophic shear banding. The creep/relaxation behaviour of the films was characterized by on-chip tensile testing, revealing an activation volume in the range 100–200 Å3. Advanced high-resolution transmission electron microscopy imaging and spectroscopy exhibit a very fine glassy nanostructure with well-defined dense Ni-rich clusters embedded in Zr-rich clusters of lower atomic density and a ~2–3 nm characteristic length scale. Nanobeam electron diffraction analysis reveals that the accumulation of plastic deformation at roomtemperature
correlates with monotonously increasing disruption of the local atomic order. These results provide experimental evidences of the dynamics of shear transformation zones activation in metallic glasses. The impact of the nanoscale structural heterogeneities on the mechanical properties including the rate dependent behaviour is discussed, shedding new light on the governing plasticity mechanisms in metallic glasses with initially heterogeneous atomic arrangement. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000486139700008 |
Publication Date |
2019-09-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.259 |
Times cited |
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Open Access |
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Notes |
H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). This work was supported by the FNRS under Grant PDR – T.0178.19. FWO project G093417N (‘Compressed sensing enabling low dose imaging in transmission electron microscopy’) and Hercules fund ‘Direct electron detector for soft matter TEM’ from Flemish Government are acknowledged. |
Approved |
Most recent IF: 4.259 |
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Call Number |
EMAT @ emat @c:irua:162786 |
Serial |
5375 |
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Permanent link to this record |
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Author |
Van Cauwenbergh, P.; Samaee, V.; Thijs, L.; Nejezchlebova, J.; Sedlak, P.; Ivekovic, A.; Schryvers, D.; Van Hooreweder, B.; Vanmeensel, K. |
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Title |
Unravelling the multi-scale structure-property relationship of laser powder bed fusion processed and heat-treated AlSi10Mg |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Scientific Reports |
Abbreviated Journal |
Sci Rep-Uk |
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Volume |
11 |
Issue |
1 |
Pages |
6423 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Tailoring heat treatments for Laser Powder Bed Fusion (LPBF) processed materials is critical to ensure superior and repeatable material properties for high-end applications. This tailoring requires in-depth understanding of the LPBF-processed material. Therefore, the current study aims at unravelling the threefold interrelationship between the process (LPBF and heat treatment), the microstructure at different scales (macro-, meso-, micro-, and nano-scale), and the macroscopic material properties of AlSi10Mg. A similar solidification trajectory applies at different length scales when comparing the solidification of AlSi10Mg, ranging from mould-casting to rapid solidification (LPBF). The similarity in solidification trajectories triggers the reason why the Brody-Flemings cellular microsegregation solidification model could predict the cellular morphology of the LPBF as-printed microstructure. Where rapid solidification occurs at a much finer scale, the LPBF microstructure exhibits a significant grain refinement and a high degree of silicon (Si) supersaturation. This study has identified the grain refinement and Si supersaturation as critical assets of the as-printed microstructure, playing a vital role in achieving superior mechanical and thermal properties during heat treatment. Next, an electrical conductivity model could accurately predict the Si solute concentration in LPBF-processed and heat-treated AlSi10Mg and allows understanding the microstructural evolution during heat treatment. The LPBF-processed and heat-treated AlSi10Mg conditions (as-built (AB), direct-aged (DA), stress-relieved (SR), preheated (PH)) show an interesting range of superior mechanical properties (tensile strength: 300-450 MPa, elongation: 4-13%) compared to the mould-cast T6 reference condition. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000632047000003 |
Publication Date |
2021-03-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.259 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 4.259 |
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Call Number |
UA @ admin @ c:irua:177634 |
Serial |
6791 |
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Permanent link to this record |
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Author |
Idrissi, H.; Samaee, V.; Lumbeeck, G.; Werf, T.; Pardoen, T.; Schryvers, D.; Cordier, P. |
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Title |
In Situ Quantitative Tensile Testing of Antigorite in a Transmission Electron Microscope |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Journal Of Geophysical Research-Solid Earth |
Abbreviated Journal |
J Geophys Res-Sol Ea |
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Volume |
125 |
Issue |
3 |
Pages |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The determination of the mechanical properties of serpentinites is essential toward the understanding of the mechanics of faulting and subduction. Here we present the first in situ tensile tests on antigorite in a transmission electron microscope. A push‐to‐pull deformation device is used to perform quantitative tensile tests, during which force and displacement are measured, while the evolving microstructure is imaged with the microscope. The experiments have been performed at room temperature on 2 × 1 × 0.2 μm3 beams prepared by focused ion beam. The specimens are not single crystals despite their small sizes. Orientation mapping indicated that several grains were well oriented for plastic slip. However, no dislocation activity has been observed even though the engineering tensile stress went up to 700 MPa. We show also that antigorite does not exhibit a purely elastic‐brittle behavior since, despite the presence of defects, the specimens accumulate permanent deformation and did not fail within the elastic regime. Instead, we observe that strain localizes at grain boundaries. All observations concur to show that under these experimental conditions, grain boundary sliding is the dominant deformation mechanism. This study sheds a new light on the mechanical properties of antigorite and calls for further studies on the structure and properties of grain boundaries in antigorite and more generally in phyllosilicates. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000530895800023 |
Publication Date |
2020-02-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2169-9313 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.9 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
We thank S. Guillot for having kindly provided us with the two antigorite samples investigated in this study. We acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program under Grant Agreement 787198—TimeMan. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR‐FNRS). We acknowledge fruitful discussions with A. Baronnet. We thank J. Gasc and an anonymous reviewer for their critical comments. Data (movies of the three in situ deformation experiments) can be downloaded (from https://doi.org/10.5281/zenodo.3583135). |
Approved |
Most recent IF: 3.9; 2020 IF: 3.35 |
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Call Number |
EMAT @ emat @c:irua:167594 |
Serial |
6355 |
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Permanent link to this record |
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Author |
Boullay, P.; Schryvers, D.; Kohn, R.V. |
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Title |
Bending martensite needles in Ni65Al35 investigated by two-dimensional elasticity and high-resolution transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2001 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
64 |
Issue |
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Pages |
144105,1-8 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000171530000026 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
18 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2001 IF: NA |
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Call Number |
UA @ lucian @ c:irua:48392 |
Serial |
227 |
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Permanent link to this record |