| Records |
| Author |
Delville, R.; Kasinathan, S.; Zhang, Z.; van Humbeeck, J.; James, R.D.; Schryvers, D. |
| Title |
Transmission electron microscopy study of phase compatibility in low hysteresis shape memory alloys |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Philosophical magazine |
Abbreviated Journal |
Philos Mag |
| Volume |
90 |
Issue |
1/4 |
Pages |
177-195 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Recent findings have linked low hysteresis in shape memory alloys with phase compatibility between austenite and martensite. To investigate the evolution of microstructure as phase compatibility increases and hysteresis is reduced, transmission electron microscopy was used to study the alloy system Ti50Ni50xPdx, where the composition is systemically tuned to approach perfect compatibility. Changes in morphology, twinning density and twinning modes are reported, along with special microstructures occurring when compatibility is achieved. In addition, the interface between austenite and a single variant of martensite was studied by high-resolution and conventional electron microscopy. The low energy configuration of the interface detailed in this article suggests that it plays an important role in the lowering of hysteresis compared to classical habit plane interfaces. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000274576500013 |
Publication Date |
2010-01-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1478-6435;1478-6443; |
ISBN |
|
Additional Links  |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.505 |
Times cited |
70 |
Open Access |
|
| Notes |
Multimat; FWO |
Approved |
Most recent IF: 1.505; 2010 IF: 1.304 |
| Call Number |
UA @ lucian @ c:irua:79859 |
Serial |
3718 |
| Permanent link to this record |
| |
|
| |
| Author |
Zelaya, E.; Schryvers, D.; Tolley, A.; Fitchner, P.F.P. |
| Title |
Cavity nucleation and growth in Cu-Zn-Al irradiated with Cu+ ions at different temperatures |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Intermetallics |
Abbreviated Journal |
Intermetallics |
| Volume |
18 |
Issue |
4 |
Pages |
493-498 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The effects of high dose ion irradiation in β CuZnAl were investigated between room temperature and 150 °C. Single crystal samples with surface normal close to [001]β were irradiated with 300 keV Cu+ ions. Microstructural changes were characterized using transmission electron microscopy. Irradiation induced cavities located on the surface exposed to the irradiation were observed. The morphology, size and density distribution of these cavities were analyzed as a function of different irradiation conditions. The shape and location of the cavities with respect to the irradiation surface were not affected by irradiation temperature or irradiation dose. Instead, the cavity size distribution showed a bi-modal shape for a dose of 15 dpa, regardless of irradiation temperature. For a dose of 30 dpa the bi-modal distribution was only observed after room temperature irradiation. The diffusion effects of vacancies produced by irradiation are analyzed in shape memory CuZnAl alloys, which main characteristic is the diffusionless martensitic transformation. Particularly, the cavity size distributions were analyzed in terms of nucleation, growth and coalescence. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Chicago, Ill. |
Editor |
|
| Language |
|
Wos |
000276058200014 |
Publication Date |
2009-10-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0966-9795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.14 |
Times cited |
1 |
Open Access |
|
| Notes |
Iaea |
Approved |
Most recent IF: 3.14; 2010 IF: 2.335 |
| Call Number |
UA @ lucian @ c:irua:80924 |
Serial |
302 |
| Permanent link to this record |
| |
|
| |
| Author |
Cao, S.; Nishida, M.; Somsen, C.; Eggeler, G.; Schryvers, D. |
| Title |
3D FIB/SEM study of Ni4Ti3 precipitates in Ni-Ti alloys with different thermal-mechanical histories |
Type |
P1 Proceeding |
| Year |
2009 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
02004,1-02004,6 |
| Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
| Abstract |
The three-dimensional size, morphology and distribution of Ni4Ti3 precipitates growing in binary Ni-rich Ni-Ti alloys have been investigated via a slice view procedure in a Dual-Beam FIB/SEM system, in order to better stress-free Ni50.8Ti49.2 alloy with all four variants of precipitates and a compressed Ni51Ti49 alloy with aligned precipitates in one family were studied. The Ni4Ti3 precipitates reach a volume fraction of 9.6% in the reconstructed region of the stress-free alloy and 4.3% in the compressed one. In both cases, the mean volume, specific surface area, sphericity and aspect ratio of the precipitates are calculated and the Pair Distribution Functions of the precipitates are obtained. It is shown that most precipitates in the stress-free sample grow larger and have a more lenticular shape, while those in the compressed sample are more cylindrical. Deviations from these ideal shapes reveal internal steps in the stress-free sample and lamellae formation in the compressed one. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
Edp |
Place of Publication |
Coutaboeuf |
Editor |
|
| Language |
|
Wos |
000274582300008 |
Publication Date |
2009-08-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:81950 c:irua:81950 |
Serial |
14 |
| Permanent link to this record |
| |
|
| |
| Author |
Delville, R.; James, R.D.; Salman, U.; Finel, A.; Schryvers, D. |
| Title |
Transmission electron microscopy study of low-hysteresis shape memory alloys |
Type |
P1 Proceeding |
| Year |
2009 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
02005,1-02005,7 |
| Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
| Abstract |
Recent findings have linked low hysteresis in shape memory alloys with phase compatibility between austenite and martensite. In order to investigate the evolution of microstructure as the phase compatibility increases and the hysteresis is reduced, transmission electron microscopy was used to study the alloy system Ti50Ni50-xPdx where the composition is systemically tuned to approach perfect compatibility. Changes in morphology, twinning density and twinning modes are reported along with special microstructures occurring when the compatibility is achieved. In addition, the interface between austenite and a single variant of martensite was studied by high-resolution and conventional electron microscopy. The atomically sharp, defect free, low energy configuration of the interface suggests that it plays an important role in the lowering of hysteresis. Finally, dynamical modeling of the martensitic transformation using the phase-field micro-elasticity model within the geometrically linear theory succeeded in reproducing the change in microstructure as the compatibility condition is satisfied. Latest results on the extension of these findings in other Ni-Ti based ternary/quaternary systems are also reported. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
Edp |
Place of Publication |
Coutaboeuf |
Editor |
|
| Language |
|
Wos |
000274582300009 |
Publication Date |
2009-08-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
3 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:81951 |
Serial |
3716 |
| Permanent link to this record |
| |
|
| |
| Author |
Idrissi, H.; Schryvers, D.; Salje, E.K.H.; Zhang, H.; Carpenter, M.A.; Moya, X. |
| Title |
Pinning of the martensitic microstructures by dislocations in Cu74.08Al23.13Be2.79 |
Type |
P1 Proceeding |
| Year |
2009 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
02029,1-02029,5 |
| Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
| Abstract |
A single crystal of Cu74.08Al23.13Be2.79 undergoes a martensitic phase transition at 246K and 232K under heating and cooling, respectively. Surprisingly, the martensite phase is elastically much harder than the austenite phase showing that interfaces between various crystallographic variants are strongly pinned and can not be moved by external stress while the phase boundary between the austenite and martensite regions in the sample remains mobile. This unusual behavior was revealed by Dynamical Mechanical Analysis and Resonant Ultrasound Spectroscopy. Transmission Electron Microscopy shows that the pinning is generated by dislocations, which are inherited from the austenite phase. Such dislocations can hinder the movement of stacking faults in the 18R martensite structure or twin boundaries between martensite variants. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
Edp |
Place of Publication |
Coutaboeuf |
Editor |
|
| Language |
|
Wos |
000274582300033 |
Publication Date |
2009-08-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
2 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:81952 |
Serial |
2626 |
| Permanent link to this record |
| |
|
| |
| Author |
Tirry, W.; Schryvers, D. |
| Title |
3D strain fields surrounding Ni4Ti3: direct measurement and correlation with the R-phase |
Type |
P1 Proceeding |
| Year |
2009 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
02032,1-02032,6 |
| Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
| Abstract |
Strain fields introduced by coherent Ni4Ti3 precipitates in austenitic Ni-Ti are believed to be a possible origin of why the R-phase transformation is introduced as an extra step before transforming to the B19'. The presence of this strain field was already confirmed in the past by conventional transmission electron microscopy (TEM) techniques and measured quantitatively by high resolution TEM (HRTEM). This time the geometrical phase method is applied on HRTEM micrographs to measure the full 3D strain tensor of the strain fields. Since each atomic resolution micrograph only results in a 2D measurement of the strain, observations in two different zone orientations are combined to retrieve the 3 x 3 strain tensor. In this work observations in a [1-1 1](B2) and [1 0-1](B2) zone orientation are used and this in case of precipitates with a diameter of around 50nm. In a next step the measured strain tensor is compared to the calculated eigenstrain of the R-phase in reference to the B2 matrix. This comparison shows that the introduced strain is very similar to the eigenstrain of one R-phase variant. Since for both structures, Ni4Ti3 and R-phase, four orientation variants are possible, each variant of the R-phase is thus able to accommodate the strain field of one of the Ni4Ti3 variants. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
Edp |
Place of Publication |
Coutaboeuf |
Editor |
|
| Language |
|
Wos |
000274582300036 |
Publication Date |
2009-08-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:81953 |
Serial |
17 |
| Permanent link to this record |
| |
|
| |
| Author |
Tian, H.; Schryvers, D.; Shabalovskaya, S.; van Humbeeck, J. |
| Title |
TEM study of the mechanism of Ni ion release from Nitinol wires with original oxides |
Type |
P1 Proceeding |
| Year |
2009 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
05027,1-05027,6 |
| Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
| Abstract |
The surface of commercial Nitinol wires with original oxides and a thickness in the 30-190 nm range was investigated by different state of art TEM techniques. The oxide surface layer was identified as a combination of TiO and TiO2 depending on the processing of the wire. Between the core of the wires and the oxidized surface, an interfacial Ni3Ti nanolayer was observed while Ni nanoparticles are found inside the original oxide. The particle sizes, their distribution in the surface and the Ti-O stoichiometry were deduced from the analysis of the obtained data. Molecular dynamics calculations performed for evaluation of the stability of Ni particles relative to the atomic state revealed that a pure Ni particle has a lower energy than free Ni atoms inside the TiO2 lattice. The obtained results are discussed with respect to surface stability and Ni release in the human body. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
Edp |
Place of Publication |
Coutaboeuf |
Editor |
|
| Language |
|
Wos |
000274582300092 |
Publication Date |
2009-08-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:81954 |
Serial |
3493 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000276523200018 |
Publication Date |
2010-01-25 |
| Series Editor |
|
Series Title |
|
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 |
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 |
| |
|
| |
| Author |
Tirry, W.; Coghe, F.; Bouvier, S.; Gasperini, M.; Rabet, L.; Schryvers, D. |
| Title |
A multi-scale characterization of deformation twins in Ti6Al4V sheet material deformed by simple shear |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Materials science and engineering: part A: structural materials: properties, microstructure and processing |
Abbreviated Journal |
Mat Sci Eng A-Struct |
| Volume |
527 |
Issue |
16/17 |
Pages |
4136-4145 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Ti6Al4V sheet material is subjected to simple shear deformation with strain ratio's of 10%, 30% and 50%. Optical microscopy, transmission electron microscopy and electron backscatter diffraction techniques are applied to study the presence and morphology of deformation twins. Only the View the MathML source type of twins seems to be present with a volume fraction below 1%. These View the MathML source twins show a high density of basal stacking faults of the ABABACAC type identified using atomic resolution transmission electron microscopy. A resolved shear stress analysis shows that twins most often occur on those planes with the highest resolved shear stresses, but that the starting texture is not beneficial for the occurrence of twins. It is further suggested that a transitory strain hardening regime observed around 530 MPa might be related with the onset of twinning. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lausanne |
Editor |
|
| Language |
|
Wos |
000278766800068 |
Publication Date |
2010-03-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-5093; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.094 |
Times cited |
20 |
Open Access |
|
| Notes |
Iap |
Approved |
Most recent IF: 3.094; 2010 IF: 2.101 |
| Call Number |
UA @ lucian @ c:irua:82291 |
Serial |
2212 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000279787100020 |
Publication Date |
2010-06-02 |
| Series Editor |
|
Series Title |
|
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 |
| |
|
| |
| Author |
Idrissi, H.; Renard, K.; Schryvers, D.; Jacques, P.J. |
| Title |
On the relationship between the twin internal structure and the work-hardening rate of TWIP steels |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Scripta materialia |
Abbreviated Journal |
Scripta Mater |
| Volume |
63 |
Issue |
10 |
Pages |
961-964 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
FeMnC and FeMnSiAl TWIP steels deformed under the same conditions exhibit different work-hardening rates. The present study investigates the microstructure of plastically deformed FeMnC and FeMnSiAl samples, particularly the internal structure of the mechanically generated twins and their topology at the grain scale. Twins in the FeMnC steel are finer and full of sessile dislocations, rendering this material distinctly stronger with an improved work-hardening rate. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000282461800003 |
Publication Date |
2010-07-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6462; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.747 |
Times cited |
145 |
Open Access |
|
| Notes |
Iap |
Approved |
Most recent IF: 3.747; 2010 IF: 2.820 |
| Call Number |
UA @ lucian @ c:irua:84472 |
Serial |
2452 |
| Permanent link to this record |
| |
|
| |
| Author |
Delville, R.; Schryvers, D. |
| Title |
Transmission electron microscopy study of combined precipitation of Ti2Ni(Pd) and Ti2Pd(Ni) in a Ti50Ni30Pd20 alloy |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Intermetallics |
Abbreviated Journal |
Intermetallics |
| Volume |
18 |
Issue |
12 |
Pages |
2353-2360 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We report a new mode of precipitation in a B19 martensitic Ti50Ni30Pd20 shape memory alloy consisting of a central Ti2Ni(Pd) precipitate surrounded by an austenite area containing Ti2Pd(Ni) precipitates. The morphology and crystallography of the precipitation area is investigated using conventional and high resolution electron microscopy. In particular, the orientation relationship and the coherency strain between the Ti2Pd(Ni) precipitate and the surrounding retained B2 matrix are discussed. A study of local composition in relation with a ternary phase diagram using X-ray energy dispersive spectroscopy with a nanoprobe gives evidences of the formation mechanism. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Chicago, Ill. |
Editor |
|
| Language |
|
Wos |
000284447500014 |
Publication Date |
2010-09-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0966-9795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.14 |
Times cited |
9 |
Open Access |
|
| Notes |
Multimat; Iap |
Approved |
Most recent IF: 3.14; 2010 IF: 2.335 |
| Call Number |
UA @ lucian @ c:irua:84473 |
Serial |
3714 |
| Permanent link to this record |
| |
|
| |
| Author |
Delville, R.; Malard, B.; Pilch, J.; Sittner, P.; Schryvers, D. |
| Title |
Transmission electron microscopy investigation of dislocation slip during superelastic cycling of NiTi wires |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
International journal of plasticity |
Abbreviated Journal |
Int J Plasticity |
| Volume |
27 |
Issue |
2 |
Pages |
282-297 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Superelastic deformation of thin NiTi wires containing various nanograined microstructures was investigated by tensile cyclic loading with in situ evaluation of electric resistivity. Defects created by the superelastic cycling in these wires were analyzed by transmission electron microscopy. The role of dislocation slip in superelastic deformation is discussed. NiTi wires having finest microstructures (grain diameter <100 nm) are highly resistant against dislocation slip, while those with fully recrystallized microstructure and grain size exceeding 200 nm are prone to dislocation slip. The density of the observed dislocation defects increases significantly with increasing grain size. The upper plateau stress of the superelastic stressstrain curves is largely grain size independent from 10 up to 1000 nm. It is hence claimed that the HallPetch relationship fails for the stress-induced martensitic transformation in this grain size range. It is proposed that dislocation slip taking place during superelastic cycling is responsible for the accumulated irreversible strains, cyclic instability and degradation of functional properties. No residual martensite phase was found in the microstructures of superelastically cycled wires by TEM and results of the in situ electric resistance measurements during straining also indirectly suggest that none or very little martensite phase remains in the studied cycled superelastic wires after unloading. The accumulation of dislocation defects, however, does not prevent the superelasticity. It only affects the shape of the stressstrain response, makes it unstable upon cycling and changes the deformation mode from localized to homogeneous. The activity of dislocation slip during superelastic deformation of NiTi increases with increasing test temperature and ultimately destroys the superelasticity as the plateau stress approaches the yield stress for slip. Deformation twins in the austenite phase ({1 1 4} compound twins) were frequently found in cycled wires having largest grain size. It is proposed that they formed in the highly deformed B19′ martensite phase during forward loading and are retained in austenite after unloading. Such twinning would represent an additional deformation mechanism of NiTi yielding residual irrecoverable strains. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000284921800007 |
Publication Date |
2010-05-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0749-6419; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.702 |
Times cited |
157 |
Open Access |
|
| Notes |
Fwo; Iap |
Approved |
Most recent IF: 5.702; 2011 IF: 4.603 |
| Call Number |
UA @ lucian @ c:irua:84651 |
Serial |
3709 |
| Permanent link to this record |
| |
|
| |
| Author |
Verleysen, E.; Bender, H.; Richard, O.; Schryvers, D.; Vandervorst, W. |
| Title |
Characterization of nickel silicides using EELS-based methods |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Journal of microscopy |
Abbreviated Journal |
J Microsc-Oxford |
| Volume |
240 |
Issue |
1 |
Pages |
75-82 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The characterization of Ni-silicides using electron energy loss spectroscopy (EELS) based methods is discussed. A series of Ni-silicide phases is examined: Ni3Si, Ni31Si12, Ni2Si, NiSi and NiSi2. The composition of these phases is determined by quantitative core-loss EELS. A study of the low loss part of the EELS spectrum shows that both the energy and the shape of the plasmon peak are characteristic for each phase. Examination of the Ni-L edge energy loss near edge structure (ELNES) shows that the ratio and the sum of the L2 and L3 white line intensities are also characteristic for each phase. The sum of the white line intensities is used to determine the trend in electron occupation of the 3d states of the phases. The dependence of the plasmon energy on the electron occupation of the 3d states is demonstrated. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000281715400009 |
Publication Date |
2010-05-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-2720; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.692 |
Times cited |
11 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.692; 2010 IF: 1.872 |
| Call Number |
UA @ lucian @ c:irua:84879 |
Serial |
329 |
| Permanent link to this record |
| |
|
| |
| 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 |
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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000287265100045 |
Publication Date |
2010-12-20 |
| Series Editor |
|
Series Title |
|
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 |
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 |
| |
|
| |
| Author |
Zelaya, E.; Schryvers, D. |
| Title |
Reducing the formation of FIB-induced FCC layers on Cu-Zn-Al austenite |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Microscopy research and technique |
Abbreviated Journal |
Microsc Res Techniq |
| Volume |
74 |
Issue |
1 |
Pages |
84-91 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The irradiation effects of thinning a sample of a Cu-Zn-Al shape memory alloy to electron transparency by a Ga+ focused ion beam were investigated. This thinning method was compared with conventional electropolishing and Ar+ ion milling. No implanted Ga was detected but surface FCC precipitation was found as a result of the focused ion beam sample preparation. Decreasing the irradiation dose by lowering the energy and current of the Ga+ ions did not lead to a complete disappearance of the FCC structure. The latter could only be removed after gentle Ar+ ion milling of the sample. It was further concluded that the precipitation of the FCC is independent of the crystallographic orientation of the surface. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000285976000012 |
Publication Date |
2010-05-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1059-910X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.147 |
Times cited |
2 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.147; 2011 IF: 1.792 |
| Call Number |
UA @ lucian @ c:irua:85994 |
Serial |
2852 |
| Permanent link to this record |
| |
|
| |
| Author |
Zelaya, E.; Schryvers, D. |
| Title |
FCC surface precipitation in Cu-Zn-Al after low angle GA+ ion irradiation |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Materials transactions |
Abbreviated Journal |
Mater Trans |
| Volume |
51 |
Issue |
12 |
Pages |
2177-2180 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The precipitation of a disordered FCC surface structure after low angle Ga+ ion irradiation during focused ion beam thinning of a B2 Cu-Zn-Al alloy with e/a=1.48 is reported. Conventional as well as high-resolution transmission electron microscopy techniques reveal FCC layers on both sides of the thinned sample. The occurrence of this structure is attributed to disordering and dezincification of the alloy resulting from the sputtering process during the irradiation. Changes in crystallographic sample orientation with respect to the incoming ion beam do not have a significant effect on the appearance of the FCC surface structure. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Sendai |
Editor |
|
| Language |
|
Wos |
000287390300009 |
Publication Date |
2010-11-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1347-5320;1345-9678; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
0.713 |
Times cited |
2 |
Open Access |
|
| Notes |
Bof; Fwo |
Approved |
Most recent IF: 0.713; 2010 IF: 0.787 |
| Call Number |
UA @ lucian @ c:irua:85997 |
Serial |
1175 |
| Permanent link to this record |
| |
|
| |
| Author |
Tian, H.; Schryvers, D.; Liu, D.; Jiang, Q.; van Humbeeck, J. |
| Title |
Stability of Ni in nitinol oxide surfaces |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Acta biomaterialia |
Abbreviated Journal |
Acta Biomater |
| Volume |
7 |
Issue |
2 |
Pages |
892-899 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The stability of Ni in titanium oxide surface layers on nitinol wires known to release certain amounts of Ni was investigated by first principles density functional theory and transmission electron microscopy. The oxides were identified as a combination of TiO and TiO2 depending on the thickness of the layer. The calculations indicate that free Ni atoms can exist in TiO at ambient temperature while Ni particles form in TiO2, which was confirmed by the transmission electron microscopy observations. The results are discussed with respect to surface stability and Ni release due to free Ni atoms and Ni particles. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
S.l. |
Editor |
|
| Language |
|
Wos |
000286707700047 |
Publication Date |
2010-09-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1742-7061; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.319 |
Times cited |
39 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 6.319; 2011 IF: 4.865 |
| Call Number |
UA @ lucian @ c:irua:85998 |
Serial |
3128 |
| Permanent link to this record |
| |
|
| |
| Author |
Vanhumbeeck, J.-F.; Tian, H.; Schryvers, D.; Proost, J. |
| Title |
Stress-assisted crystallisation in anodic titania |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Corrosion science |
Abbreviated Journal |
Corros Sci |
| Volume |
53 |
Issue |
4 |
Pages |
1269-1277 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| 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. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000288972000016 |
Publication Date |
2010-12-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0010-938X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.245 |
Times cited |
11 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 5.245; 2011 IF: 3.734 |
| Call Number |
UA @ lucian @ c:irua:88385 |
Serial |
3177 |
| Permanent link to this record |
| |
|
| |
| Author |
Tian, H.; Schryvers, D.; Claeys, P. |
| Title |
Nanodiamonds do not provide unique evidence for a Younger Dryas impact |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Proceedings of the National Academy of Sciences of the United States of America |
Abbreviated Journal |
P Natl Acad Sci Usa |
| Volume |
108 |
Issue |
1 |
Pages |
40-44 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Microstructural, δ13C isotope and C/N ratio investigations were conducted on excavated material from the black Younger Dryas boundary in Lommel, Belgium, aiming for a characterisation of the carbon content and structures. Cubic diamond nanoparticles are found in large numbers. The larger ones with diameters around or above 10 nm often exhibit single or multiple twins. The smaller ones around 5 nm in diameter are mostly defect-free. Also larger flake-like particles, around 100 nm in lateral dimension, with a cubic diamond structure are observed as well as large carbon onion structures. The combination of these characteristics does not yield unique evidence for an exogenic impact related to the investigated layer. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000285915000012 |
Publication Date |
2010-12-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0027-8424;1091-6490; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
9.661 |
Times cited |
32 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 9.661; 2011 IF: 9.681 |
| Call Number |
UA @ lucian @ c:irua:88733 |
Serial |
2254 |
| Permanent link to this record |
| |
|
| |
| Author |
Verleysen, E.; Bender, H.; Richard, O.; Schryvers, D.; Vandervorst, W. |
| Title |
Compositional characterization of nickel silicides by HAADF-STEM imaging |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of materials science |
Abbreviated Journal |
J Mater Sci |
| Volume |
46 |
Issue |
7 |
Pages |
2001-2008 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A methodology for the quantitative compositional characterization of nickel silicides by high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) imaging is presented. HAADF-STEM images of a set of nickel silicide reference samples Ni3Si, Ni31Si12, Ni2Si, NiSi and NiSi2 are taken at identical experimental conditions. The correlation between sample thickness and HAADF-STEM intensity is discussed. In order to quantify the relationship between the experimental Z-contrast intensities and the composition of the analysed layers, the ratio of the HAADF-STEM intensity to the sample thickness or to the intensity of the silicon substrate is determined for each nickel silicide reference sample. Diffraction contrast is still detected on the HAADF-STEM images, even though the detector is set at the largest possible detection angle. The influence on the quantification results of intensity fluctuations caused by diffraction contrast and channelling is examined. The methodology is applied to FUSI gate devices and to horizontal TFET devices with different nickel silicides formed on source, gate and drain. It is shown that, if the elements which are present are known, this methodology allows a fast quantitative 2-dimensional compositional analysis. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000286633000002 |
Publication Date |
2011-01-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-2461;1573-4803; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.599 |
Times cited |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.599; 2011 IF: 2.015 |
| Call Number |
UA @ lucian @ c:irua:88950 |
Serial |
446 |
| Permanent link to this record |
| |
|
| |
| Author |
Idrissi, H.; Wang, B.; Colla, M.S.; Raskin, J.P.; Schryvers, D.; Pardoen, T. |
| Title |
Ultrahigh strain hardening in thin palladium films with nanoscale twins |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
| Volume |
23 |
Issue |
18 |
Pages |
2119-2122 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Nanocrystalline Pd thin films containing coherent growth twin boundaries are deformed using on-chip nanomechanical testing. A large work-hardening capacity is measured. The origin of the observed behavior is unraveled using transmission electron microscopy and shows specific dislocations and twin boundaries interactions. The results indicate the potential for large strength and ductility balance enhancement in Pd films, as needed in membranes for H technologies. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000291164200013 |
Publication Date |
2011-04-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0935-9648; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
19.791 |
Times cited |
57 |
Open Access |
|
| Notes |
Iap |
Approved |
Most recent IF: 19.791; 2011 IF: 13.877 |
| Call Number |
UA @ lucian @ c:irua:90103 |
Serial |
3794 |
| Permanent link to this record |
| |
|
| |
| Author |
Cao, S.; Nishida, M.; Schryvers, D. |
| Title |
FIB/SEM applied to quantitative 3D analysis of precipitates in Ni-Ti |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Diffusion and defect data : solid state data : part B : solid state phenomena |
Abbreviated Journal |
|
| Volume |
172/174 |
Issue |
|
Pages |
1284-1289 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Ni4Ti3 precipitates with a heterogeneous distribution growing in a polycrystalline Ni50.8Ti49.2 alloy have been investigated in a Dual-Beam FIB/SEM system. The volume ratio, 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 or calculated. The morphology of the precipitates was classified according to the Zingg scheme. The multistage martensitic transformation occurring in these kinds of samples is interpreted in view of the data of this heterogeneous microstructure of matrix and precipitates. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Vaduz |
Editor |
|
| Language |
|
Wos |
000303359700199 |
Publication Date |
2011-07-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1662-9779; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:90152 |
Serial |
1188 |
| Permanent link to this record |
| |
|
| |
| Author |
Schryvers, D.; Tirry, W.; Cao, S. |
| Title |
Advanced TEM and SEM methods applied to 3D nano- and microstructural investigations of Ni4Ti3 precipitates in Ni-Ti (SMA) |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Diffusion and defect data : solid state data : part B : solid state phenomena |
Abbreviated Journal |
|
| Volume |
172/174 |
Issue |
|
Pages |
229-235 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Two different kinds of experimental approaches yielding three-dimensional structural information on metastable semi-coherent precipitates are demonstrated. By combining high-resolution images from two independent viewing directions a full description of the strain field surrounding a nano-sized Ni4Ti3 precipitate in Ni-Ti can be obtained. The principal axes and strains correlate well with the transformation strain of the observed R-phase transformation close to the precipitate. Using a slice-and-view procedure in a FIB/SEM dual-beam instrument, a three-dimensional voxel dataset is produced from which morphological and distributional information on the same precipitates can be obtained yielding new insight into the particular transformation paths of these alloys, relevant for their functional behaviour. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Vaduz |
Editor |
|
| Language |
|
Wos |
000303359700036 |
Publication Date |
2011-07-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1662-9779; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:90153 |
Serial |
73 |
| Permanent link to this record |
| |
|
| |
| Author |
Delville, R.; Malard, B.; Pilch, J.; Sittner, P.; Schryvers, D. |
| Title |
Transmission electron microscopy study of microstructural evolution in nanograined Ni-Ti microwires heat treated by electric pulse |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Diffusion and defect data : solid state data : part B : solid state phenomena |
Abbreviated Journal |
|
| Volume |
172/174 |
Issue |
|
Pages |
682-687 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Transmission electron microscopy and mechanical testing were employed to investigate the evolution of microstructure and functional superelastic properties of 0.1mm diameter as-drawn Ni-Ti wires subjected to a non-conventional heat treatment by controlled electric pulse current. This method enables a finer control of the recovery and recrystallisation processes taking place during the heat treatment and accordingly a better control on the final microstructure. The best functional properties were obtained for heat-treated Ni-Ti wires having a nanograined microstructure (20-50 nm) partially recovered through polygonization and partially recrystallized. Such microstructure is highly resistant against dislocation slip upon cycling, while microstructures annealed for longer time and showing mostly recrystallized grains were prone to dislocation slip, particularly as the grain size exceeds 100 nm. The density of dislocation defects increased significantly with increasing grain size of the microstructure. The activity of three <100>/{011} slip systems was identified in the largest grains of 500-1200 nm. An additional mode of plastic deformation, {114} compound austenite twinning, was observed in the largest grains of fully recrystallized microstructures. It is proposed that dislocation slip (and possibly deformation twinning) occurring in superelastic cycling is coupled with the stress-induced martensitic transformation. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Vaduz |
Editor |
|
| Language |
|
Wos |
000303359700105 |
Publication Date |
2011-07-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1662-9779; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
3 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:90154 |
Serial |
3717 |
| Permanent link to this record |
| |
|
| |
| Author |
Delville, R.; Shi, H.; James, R.D.; Schryvers, D. |
| Title |
Special microstructures and twin features in Ti50Ni50-x(Pd,Au)x at small hysteresis |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Diffusion and defect data : solid state data : part B : solid state phenomena |
Abbreviated Journal |
|
| Volume |
172/174 |
Issue |
|
Pages |
105-110 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The breaking of symmetry due to atomic displacements in the austenite-martensite phase transformation generally leads to their crystallographic incompatibility. Energy minimizing accommodation mechanisms such as martensite twinning have been recently shown to be a source of hysteresis and irreversible plastic deformation. Compatibility between the two phases can however be achieved by carefully tuning lattice parameters through composition change. A dramatic drop in hysteresis and novel microstructures such as a lowering of the amount of twin lamella are then observed. Related theoretical and simulation works also support the existence of such microstructures including peculiar self-accommodating configurations at near-compatibility. We present the transmission electron microscopy (TEM) study of these novel microstructures for the alloy systems Ti50Ni50-xPdx and Ti50Ni50-xAux where the composition was systemically tuned to approach perfect compatibility. High resolution imaging of the interface between austenite and martensite supplies evidences of compatibility at the atomic level. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Vaduz |
Editor |
|
| Language |
|
Wos |
000303359700016 |
Publication Date |
2011-07-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1662-9779; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
3 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:90155 |
Serial |
3069 |
| 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. |
| Title |
A weak compatibility condition for precipitation with application to the microstructure of PbTe-Sb2Te3 thermoelectrics |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
| Volume |
59 |
Issue |
15 |
Pages |
6124-6132 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| 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. |
| 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 |
000294086900026 |
Publication Date |
2011-07-22 |
| Series Editor |
|
Series Title |
|
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 |
8 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 5.301; 2011 IF: 3.755 |
| Call Number |
UA @ lucian @ c:irua:92388 |
Serial |
3911 |
| Permanent link to this record |
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| |
| Author |
Idrissi, H.; Turner, S.; Mitsuhara, M.; Wang, B.; Hata, S.; Coulombier, M.; Raskin, J.-P.; Pardoen, T.; Van Tendeloo, G.; Schryvers, D. |
| Title |
Point defect clusters and dislocations in FIB irradiated nanocrystalline aluminum films : an electron tomography and aberration-corrected high-resolution ADF-STEM study |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
| Volume |
17 |
Issue |
6 |
Pages |
983-990 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Focused ion beam (FIB) induced damage in nanocrystalline Al thin films has been characterized using advanced transmission electron microscopy techniques. Electron tomography was used to analyze the three-dimensional distribution of point defect clusters induced by FIB milling, as well as their interaction with preexisting dislocations generated by internal stresses in the Al films. The atomic structure of interstitial Frank loops induced by irradiation, as well as the core structure of Frank dislocations, has been resolved with aberration-corrected high-resolution annular dark-field scanning TEM. The combination of both techniques constitutes a powerful tool for the study of the intrinsic structural properties of point defect clusters as well as the interaction of these defects with preexisting or deformation dislocations in irradiated bulk or nanostructured materials. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Cambridge, Mass. |
Editor |
|
| Language |
|
Wos |
000297832300018 |
Publication Date |
2011-10-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1431-9276;1435-8115; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.891 |
Times cited |
25 |
Open Access |
|
| Notes |
Iap; Fwo |
Approved |
Most recent IF: 1.891; 2011 IF: 3.007 |
| Call Number |
UA @ lucian @ c:irua:93627 |
Serial |
2653 |
| Permanent link to this record |
| |
|
| |
| Author |
Van Aert, S.; Turner, S.; Delville, R.; Schryvers, D.; Van Tendeloo, G.; Salje, E.K.H. |
| Title |
Direct observation of ferrielectricity at ferroelastic domain boundaries in CaTiO3 by electron microscopy |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
| Volume |
24 |
Issue |
4 |
Pages |
523-527 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
High-resolution aberration-corrected transmission electron microscopy aided by statistical parameter estimation theory is used to quantify localized displacements at a (110) twin boundary in orthorhombic CaTiO3. The displacements are 36 pm for the Ti atoms and confined to a thin layer. This is the first direct observation of the generation of ferroelectricity by interfaces inside this material which opens the door for domain boundary engineering. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000299156400011 |
Publication Date |
2011-12-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0935-9648; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
19.791 |
Times cited |
150 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 19.791; 2012 IF: 14.829 |
| Call Number |
UA @ lucian @ c:irua:94110 |
Serial |
717 |
| Permanent link to this record |
| |
|
| |
| 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 |
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 |
|
| Language |
|
Wos |
000301989500035 |
Publication Date |
2012-02-02 |
| Series Editor |
|
Series Title |
|
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 |
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 |
