|
Records |
Links |
|
Author |
Amin-Ahmadi, B.; Connétable, D.; Fivel, M.; Tanguy, D.; Delmelle, R.; Turner, S.; Malet, L.; Godet, S.; Pardoen, T.; Proost, J.; Schryvers, D.; Idrissi, H. |
|
|
Title |
Dislocation/hydrogen interaction mechanisms in hydrided nanocrystalline palladium films |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
|
Volume |
111 |
Issue |
111 |
Pages |
253-261 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
The nanoscale plasticity mechanisms activated during hydriding cycles in sputtered nanocrystalline Pd films have been investigated ex-situ using advanced transmission electron microscopy techniques. The internal stress developing within the films during hydriding has been monitored in-situ. Results showed that in Pd films hydrided to β-phase, local plasticity was mainly controlled by dislocation activity in spite of the small grain size. Changes of the grain size distribution and the crystallographic texture have not been observed. In contrast, significant microstructural changes were not observed in Pd films hydrided to α-phase. Moreover, the effect of hydrogen loading on the nature and density of dislocations has been investigated using aberration-corrected TEM. Surprisingly, a high density of shear type stacking faults has been observed after dehydriding, indicating a significant effect of hydrogen on the nucleation energy barriers of Shockley partial dislocations. Ab-initio calculations of the effect of hydrogen on the intrinsic stable and unstable stacking fault energies of palladium confirm the experimental observations. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000375812100027 |
Publication Date |
2016-04-06 |
|
|
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 |
14 |
Open Access |
|
|
|
Notes |
This work was carried out in the framework of the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs, under Contract No. P7/21. The support of the FWO research project G012012N “Understanding nanocrystalline mechanical behaviour from structural investigations” for B. Amin-Ahmadi is also gratefully acknowledged. This work was granted access to the HPC resources of CALMIP (CICT Toulouse, France) under the allocations 2014-p0912 and 2014-p0749. |
Approved |
Most recent IF: 5.301 |
|
|
Call Number |
c:irua:132678 |
Serial |
4054 |
|
Permanent link to this record |
|
|
|
|
Author |
Baral, P.; Orekhov, A.; Dohmen, R.; Coulombier, M.; Raskin, J.P.; Cordier, P.; Idrissi, H.; Pardoen, T. |
|
|
Title |
Rheology of amorphous olivine thin films characterized by nanoindentation |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Acta Materialia |
Abbreviated Journal |
Acta Mater |
|
|
Volume |
219 |
Issue |
|
Pages |
117257 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
The rheological properties of amorphous olivine thin films deposited by pulsed laser deposition have been studied based on ambient temperature nanoindentation under constant strain-rate as well as re-laxation conditions. The amorphous olivine films exhibit a viscoelastic-viscoplastic behavior with a significant rate dependency. The strain-rate sensitivity m is equal to similar to 0 . 05 which is very high for silicates, indicating a complex out-of-equilibrium structure. The minimum apparent activation volume determined from nanoindentation experiments corresponds to Mg and Fe atomic metallic sites in the (Mg,Fe)(2)SiO4 crystalline lattice. The ambient temperature creep behavior of the amorphous olivine films differs very much from the one of single crystal olivine. This behavior directly connects to the recent demonstration of the activation of grain boundary sliding in polycrystalline olivine following grain boundary amorphization under high-stress. (C) 2021 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000706867800004 |
Publication Date |
2021-08-19 |
|
|
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 |
|
Open Access |
OpenAccess |
|
|
Notes |
|
Approved |
Most recent IF: 5.301 |
|
|
Call Number |
UA @ admin @ c:irua:182592 |
Serial |
6882 |
|
Permanent link to this record |
|
|
|
|
Author |
Samaee, V.; Sandfeld, S.; Idrissi, H.; Groten, J.; Pardoen, T.; Schwaiger, R.; Schryvers, D. |
|
|
Title |
Dislocation structures and the role of grain boundaries in cyclically deformed Ni micropillars |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
Materials Science And Engineering A-Structural Materials Properties Microstructure And Processing |
Abbreviated Journal |
Mat Sci Eng A-Struct |
|
|
Volume |
769 |
Issue |
|
Pages |
138295 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Transmission electron microscopy and finite element-based dislocation simulations were combined to study the development of dislocation microstructures after cyclic deformation of single crystal and bicrystal Ni micropillars oriented for multi-slip. A direct correlation between large accumulation of plastic strain and the presence of dislocation cell walls in the single crystal micropillars was observed, while the presence of the grain boundary hampered the formation of wall-like structures in agreement with a smaller accumulated plastic strain. Automated crystallographic orientation and nanostrain mapping using transmission electron microscopy revealed the presence of lattice heterogeneities associated to the cell walls including long range elastic strain fields. By combining the nanostrain mapping with an inverse modelling approach, information about dislocation density, line orientation and Burgers vector direction was derived, which is not accessible otherwise in such dense dislocation structures. Simulations showed that the image forces associated with the grain boundary in this specific bicrystal configuration have only a minor influence on dislocation behavior. Thus, the reduced occurrence of “mature” cell walls in the bicrystal can be attributed to the available volume, which is too small to accommodate cell structures. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000500373800018 |
Publication Date |
2019-08-21 |
|
|
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 |
6.4 |
Times cited |
1 |
Open Access |
OpenAccess |
|
|
Notes |
Financial support from the Flemish (FWO) and German Research Foundation (DFG) through the European M-ERA.NET project “FaSS” (Fatigue Simulation near Surfaces) under the grant numbers GA.014.13 N,SCHW855/5-1, and SA2292/2-1 is gratefully acknowledged. V.S. acknowledges the FWO research project G012012 N “Understanding nanocrystalline mechanical behaviour from structural investigations”. H.I. is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). S.S. acknowledges financial support from the European Research Council through the ERC Grant Agreement No. 759419 (MuDiLingo – A Multiscale Dislocation Language for Data- Driven Materials Science). |
Approved |
Most recent IF: 6.4; 2020 IF: 3.094 |
|
|
Call Number |
EMAT @ emat @c:irua:163475 |
Serial |
5371 |
|
Permanent link to this record |
|
|
|
|
Author |
Delmelle, R.; Amin-Ahmadi, B.; Sinnaeve, M.; Idrissi, H.; Pardoen, T.; Schryvers, D.; Proost, J. |
|
|
Title |
Effect of structural defects on the hydriding kinetics of nanocrystalline Pd thin films |
Type |
A1 Journal article |
|
Year |
2015 |
Publication |
International journal of hydrogen energy |
Abbreviated Journal |
Int J Hydrogen Energ |
|
|
Volume |
40 |
Issue |
40 |
Pages |
7335-7347 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
While the microstructure of a metal is well-known to affect its equilibrium hydrogen uptake and therefore the hydriding thermodynamics, microstructural effects on the hydriding kinetics are much less documented. Moreover, for thin film systems, such microstructural effects are difficult to separate from the internal stress effect, since most defects generate internal stresses. Such a decoupling has been achieved in this paper for nanocrystalline Pd thin film model systems through the use of a high-resolution, in-situ curvature measurement set-up during Pd deposition, annealing and hydriding. This set-up allowed producing Pd thin films with similar internal stress levels but significantly different microstructures. This was evidenced from detailed defect statistics obtained by transmission electron microscopy, which showed that the densities of grain boundaries, dislocations and twin boundaries have all been lowered by annealing. The same set-up was then used to study the hydriding equilibrium and kinetic behaviour of the resulting films at room temperature. A full quantitative analysis of their hydriding cycles showed that the rate constants of both the adsorption- and absorption-limited kinetic regimes were strongly affected by microstructure. Defect engineering was thereby shown to increase the rate constants for hydrogen adsorption and absorption in Pd by a factor 40 and 30, respectively. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
|
|
Language |
|
Wos |
000355884300012 |
Publication Date |
2015-05-02 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0360-3199; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.582 |
Times cited |
13 |
Open Access |
|
|
|
Notes |
Iap 7/21 |
Approved |
Most recent IF: 3.582; 2015 IF: 3.313 |
|
|
Call Number |
c:irua:126429 |
Serial |
838 |
|
Permanent link to this record |