Records |
Author |
Malard, B.; Pilch, J.; Sittner, P.; Delville, R.; Curfs, C. |
Title |
In situ investigation of the fast microstructure evolution during electropulse treatment of cold drawn NiTi wires |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
59 |
Issue |
4 |
Pages |
1542-1556 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Microstructural changes taking place during the heat treatment of cold-worked NiTi alloy are of key interest in shape memory alloy technology, since they are responsible for setting the austenite shape and functional properties of the heat-treated alloy. In this work, microstructural evolution during non-conventional electropulse heat treatment of thin NiTi filaments was investigated in a unique high-speed in situ synchrotron X-ray diffraction experiment with simultaneous evaluation of the tensile force and electrical resistivity of the treated wire. The in situ results provide direct experimental evidence on the evolution of the internal stress and density of defects during fast heating from 20 °C to ∼700 °C. This evidence is used to characterize a sequence of dynamic recovery and recrystallization processes responsible for the microstructure and superelastic functional property changes during the electropulse treatments. |
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 |
|
Language |
|
Wos |
000287265100023 |
Publication Date |
2010-12-11 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
48 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.301; 2011 IF: 3.755 |
Call Number |
UA @ lucian @ c:irua:98372 |
Serial |
1583 |
Permanent link to this record |
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|
Author |
Delville, R.; Malard, B.; Pilch, J.; Schryvers, D. |
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 |
Year |
2010 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
58 |
Issue |
13 |
Pages |
4503-4515 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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. |
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 |
000279787100020 |
Publication Date |
2010-06-02 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
110 |
Open Access |
|
Notes |
Multimat; FWO
IAA |
Approved |
Most recent IF: 5.301; 2010 IF: 3.791 |
Call Number |
UA @ lucian @ c:irua:83279 |
Serial |
2062 |
Permanent link to this record |
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Author |
Idrissi, H.; Renard, K.; Ryelandt, L.; Schryvers, D.; Jacques, P.J. |
Title |
On the mechanism of twin formation in FeMnC TWIP steels |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
58 |
Issue |
7 |
Pages |
2464-2476 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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. |
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 |
000276523200018 |
Publication Date |
2010-01-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
244 |
Open Access |
|
Notes |
Iap |
Approved |
Most recent IF: 5.301; 2010 IF: 3.791 |
Call Number |
UA @ lucian @ c:irua:82270 |
Serial |
2441 |
Permanent link to this record |
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|
|
Author |
Bartova, B.; Wiese, N.; Schryvers, D.; Chapman, J.N.; Ignacova, S. |
Title |
Microstructure of precipitates and magnetic domain structure in an annealed Co38Ni33Al29 shape memory alloy |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
56 |
Issue |
16 |
Pages |
4470-4476 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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. |
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 |
000259931300033 |
Publication Date |
2008-06-11 |
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 |
|
Edition |
|
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
23 |
Open Access |
|
Notes |
Multimat |
Approved |
Most recent IF: 5.301; 2008 IF: 3.729 |
Call Number |
UA @ lucian @ c:irua:72321 |
Serial |
2072 |
Permanent link to this record |
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Author |
Yang, Z.; Tirry, W.; Lamoen, D.; Kulkova, S.; Schryvers, D. |
Title |
Electron energy-loss spectroscopy and first-principles calculation studies on a Ni-Ti shape memory alloy |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
56 |
Issue |
3 |
Pages |
395-404 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
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 |
|
Language |
|
Wos |
000253020900011 |
Publication Date |
2007-12-01 |
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 |
|
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
20 |
Open Access |
|
Notes |
Goa; Ec Rtn; Fwo |
Approved |
Most recent IF: 5.301; 2008 IF: 3.729 |
Call Number |
UA @ lucian @ c:irua:67462 |
Serial |
931 |
Permanent link to this record |
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Author |
Rotaru, G.-M.; Tirry, W.; Sittner, P.; van Humbeeck, J.; Schryvers, D. |
Title |
Microstructural study of equiatomic PtTi martensite and the discovery of a new long-period structure |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
55 |
Issue |
13 |
Pages |
4447-4454 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
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 |
000248436400021 |
Publication Date |
2007-06-04 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
7 |
Open Access |
|
Notes |
Fwo G.0465.05; Multimat |
Approved |
Most recent IF: 5.301; 2007 IF: 3.624 |
Call Number |
UA @ lucian @ c:irua:65849 |
Serial |
2047 |
Permanent link to this record |
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Author |
Viart, N.; Sayed Hassan, R.; Ulhaq-Bouillet, C.; Meny, C.; Panissod, P.; Loison, J.L.; Versini, G.; Huber, F.; Pourroy, G.; Verbeeck, J.; Van Tendeloo, G. |
Title |
Oxidation processes at the metal/oxide interface in CoFe2/CoFe2O4 bilayers deposited by pulsed laser deposition |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
54 |
Issue |
1 |
Pages |
191-196 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
CoFe2/CoFe2O4 bilayers were made by pulsed laser ablation of a CoFe2 target on Si(I 0 0) substrates. The metallic layer was deposited first, in vacuum. The oxide was then deposited in an oxidizing O-2:N-2 (20:80) atmosphere. Two different procedures were used for the introduction of the oxidizing atmosphere in the deposition chamber: the laser ablation of the target was either stopped (discontinuous deposition process) or maintained (continuous deposition process) during the 20 min necessary for the establishment of the desired O-2:N-2 pressure. In both cases, the different electronegativities of Fe and Co cause an important modification of the Fe/Co ratio at the metal/oxide interface, with a depletion of Fe in the metal region and of Co in the oxide region. In the continuous procedure, the combination of the kinetic energy given by the ablation process to the Fe and Co adatoms with the one they get from their different affinity towards oxidation allows the formation of a low roughness metal/oxide interface with a high (111) preferred orientation of the CoFe2O4 layer, an induced re-crystallisation of the metal layer underneath and an unusual antiferromagnetic metal/oxide magnetic coupling. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
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 |
000233784500021 |
Publication Date |
2005-10-15 |
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 |
|
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.301; 2006 IF: 3.549 |
Call Number |
UA @ lucian @ c:irua:56043UA @ admin @ c:irua:56043 |
Serial |
2540 |
Permanent link to this record |
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|
|
Author |
Tirry, W.; Schryvers, D. |
Title |
Quantitative determination of strain fields around Ni4Ti3 precipitates in NiTi |
Type |
A1 Journal article |
Year |
2005 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
53 |
Issue |
4 |
Pages |
1041-1049 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000226774500014 |
Publication Date |
2004-12-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
97 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.301; 2005 IF: 3.430 |
Call Number |
UA @ lucian @ c:irua:55686 |
Serial |
2750 |
Permanent link to this record |