Records |
Author |
Tirumalasetty, G.K.; van Huis, M.A.; Kwakernaak, C.; Sietsma, J.; Sloof, W.G.; Zandbergen, H.W. |
Title |
Deformation-induced austenite grain rotation and transformation in TRIP-assisted steel |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
60 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
3 |
Pages |
1311-1321 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Uniaxial straining experiments were performed on a rolled and annealed Si-alloyed TRIP (transformation-induced plasticity) steel sheet in order to assess the role of its microstructure on the mechanical stability of austenite grains with respect to martensitic transformation. The transformation behavior of individual metastable austenite grains was studied both at the surface and inside the bulk of the material using electron back-scattered diffraction (EBSD) and X-ray diffraction (XRD) by deforming the samples to different strain levels up to about 20%. A comparison of the XRD and EBSD results revealed that the retained austenite grains at the surface have a stronger tendency to transform than the austenite grains in the bulk of the material. The deformation-induced changes of individual austenite grains before and after straining were monitored with EBSD. Three different types of austenite grains can be distinguished that have different transformation behaviors: austenite grains at the grain boundaries between ferrite grains, twinned austenite grains, and embedded austenite grains that are completely surrounded by a single ferrite grain. It was found that twinned austenite grains and the austenite grains present at the grain boundaries between larger ferrite grains typically transform first, i.e. are less stable, in contrast to austenite grains that are completely embedded in a larger ferrite grain. In the latter case, straining leads to rotations of the harder austenite grain within the softer ferrite matrix before the austenite transforms into martensite. The analysis suggests that austenite grain rotation behavior is also a significant factor contributing to enhancement of the ductility. (C) 2011 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 |
000301157900054 |
Publication Date |
2011-12-19 |
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 |
80 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.301; 2012 IF: 3.941 |
Call Number |
UA @ lucian @ c:irua:97210 |
Serial |
630 |
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 ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
3 |
Pages |
395-404 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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 |
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 |
|
Series Issue |
|
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 |
Colla, M.-S.; Wang, B.; Idrissi, H.; Schryvers, D.; Raskin, J.-P.; Pardoen, T. |
Title |
High strength-ductility of thin nanocrystalline palladium films with nanoscale twins : on-chip testing and grain aggregate model |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
60 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
4 |
Pages |
1795-1806 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The mechanical behaviour of thin nanocrystalline palladium films with an ∼30 nm in plane grain size has been characterized on chip under uniaxial tension. The films exhibit a large strain hardening capacity and a significant increase in the strength with decreasing thickness. Transmission electron microscopy has revealed the presence of a moderate density of growth nanotwins interacting with dislocations. A semi-analytical grain aggregate model is proposed to investigate the impact of different contributions to the flow behaviour, involving the effect of twins, of grain size and of the presence of a thin surface layer. This model provides guidelines to optimizing the strength/ductility ratio of the films. |
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 |
000301989500035 |
Publication Date |
2012-02-02 |
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 |
38 |
Open Access |
|
Notes |
Iap |
Approved |
Most recent IF: 5.301; 2012 IF: 3.941 |
Call Number |
UA @ lucian @ c:irua:94213 |
Serial |
1465 |
Permanent link to this record |
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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 ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
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 |
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Language |
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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 |
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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 |
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 |
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 ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
4 |
Pages |
1041-1049 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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 |
|
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 |
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Author |
Cao, S.; Nishida, M.; Schryvers, D. |
Title |
Quantitative three-dimensional analysis of Ni4Ti3 precipitate morphology and distribution in polycrystalline Ni-Ti |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
59 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
4 |
Pages |
1780-1789 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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. |
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 |
000287265100045 |
Publication Date |
2010-12-20 |
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 |
34 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 5.301; 2011 IF: 3.755 |
Call Number |
UA @ lucian @ c:irua:85533 |
Serial |
2766 |
Permanent link to this record |
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Author |
Boullay, P.; Schryvers, D.; Ball, J.M. |
Title |
Nano-structures at martensite macrotwin interfaces in Ni65Al35 |
Type |
A1 Journal article |
Year |
2003 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
51 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
5 |
Pages |
1421-1436 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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. |
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 |
000181677700018 |
Publication Date |
2003-03-14 |
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 |
31 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.301; 2003 IF: 3.059 |
Call Number |
UA @ lucian @ c:irua:48364 |
Serial |
2248 |
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 ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
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 |
Wang, X.; Kustov, S.; Li, K.; Schryvers, D.; Verlinden, B.; Van Humbeeck, J. |
Title |
Effect of nanoprecipitates on the transformation behavior and functional properties of a Ti50.8 at.% Ni alloy with micron-sized grains |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
82 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
82 |
Pages |
224-233 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
In order to take advantage of both grain refinement and precipitation hardening effects, nanoscaled Ni4Ti3 precipitates are introduced in a Ti50.8 at.% Ni alloy with micron-sized grains (average grain size of 1.7 μm). Calorimetry, electrical resistance studies and thermomechanical tests were employed to study the transformation behavior and functional properties in relation to the obtained microstructure. A significant suppression of martensite transformation by the obtained microstructure is observed. The thermomechanical tests show that the advantageous properties of both grain refinement and precipitation hardening are combined in the developed materials, resulting in superior shape memory characteristics and stability of pseudoelasticity. It is concluded that introducing nanoscaled Ni4Ti3 precipitates into small grains is a new approach to improve the functional properties of NiTi shape memory alloys. |
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 |
000347017800021 |
Publication Date |
2014-10-04 |
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 |
51 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 5.301; 2015 IF: 4.465 |
Call Number |
c:irua:120469 |
Serial |
824 |
Permanent link to this record |