| Records |
| Author |
Samaee, V.; Gatti, R.; Devincre, B.; Pardoen, T.; Schryvers, D.; Idrissi, H. |
| Title |
Dislocation driven nanosample plasticity: new insights from quantitative in-situ TEM tensile testing |
Type |
A1 Journal Article |
| Year |
2018 |
Publication |
Scientific Reports |
Abbreviated Journal |
Sci Rep-Uk |
| Volume |
8 |
Issue |
1 |
Pages |
12012 |
| Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
| Abstract |
Intrinsic dislocation mechanisms in the vicinity of free surfaces of an almost FIB damage-free single crystal Ni sample have been quantitatively investigated owing to a novel sample preparation method combining twin-jet electro-polishing, in-situ TEM heating and FIB. The results reveal that the small-scale plasticity is mainly controlled by the conversion of few tangled dislocations, still present after heating, into stable single arm sources (SASs) as well as by the successive operation of these sources. Strain hardening resulting from the operation of an individual SAS is reported and attributed to the decrease of the length of the source. Moreover, the impact of the shortening of the dislocation source on the intermittent plastic flow, characteristic of SASs, is discussed. These findings provide essential information for the understanding of the regime of ‘dislocation source’ controlled plasticity and the related mechanical size effect. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000460200900001 |
Publication Date |
2018-08-07 |
| Series Editor |
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Series Title  |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.259 |
Times cited |
9 |
Open Access |
Not_Open_Access |
| Notes |
Financial support from the Flemish (FWO) and German Research Foundation (DFG) through the European M-ERA.NET project “FaSS” (Fatigue Simulation near Surfaces) under the grant numbers GA.014.13 N and SCHW855/5-1, respectively, is gratefully acknowledged. V. Samaee also acknowledges the FWO research project G012012N “Understanding nanocrystalline mechanical behaviour from structural investigations”. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). Dr. Ruth Schwaiger is acknowledged for providing the Ni foils used to prepare the in-situ TEM tensile specimens. |
Approved |
Most recent IF: 4.259 |
| Call Number |
EMAT @ emat @c:irua:155772 |
Serial |
5136 |
| Permanent link to this record |
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| Author |
Lumbeeck, G.; Idrissi, H.; Amin-Ahmadi, B.; Favache, A.; Delmelle, R.; Samaee, V.; Proost, J.; Pardoen, T.; Schryvers, D. |
| Title |
Effect of hydriding induced defects on the small-scale plasticity mechanisms in nanocrystalline palladium thin films |
Type |
A1 Journal Article |
| Year |
2018 |
Publication |
Journal Of Applied Physics |
Abbreviated Journal |
J Appl Phys |
| Volume |
124 |
Issue |
22 |
Pages |
225105 |
| Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
| Abstract |
Nanoindentation tests performed on nanocrystalline palladium films subjected to hydriding/dehydriding cycles demonstrate a significant softening when compared to the as-received material. The origin of this softening is unraveled by combining in situ TEM nanomechanical testing with automated crystal orientation mapping in TEM and high resolution TEM. The softening is attributed to the presence of a high density of stacking faults and of Shockley partial dislocations after hydrogen loading. The hydrogen induced defects affect the elementary plasticity mechanisms and the mechanical response by acting as preferential sites for twinning/detwinning during deformation. These results are analyzed and compared to previous experimental and simulation works in the literature. This study provides new insights into the effect of hydrogen on the atomistic deformation and cracking mechanisms as well as on the mechanical properties of nanocrystalline thin films and membranes. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000453254000025 |
Publication Date |
2018-12-14 |
| 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 |
0021-8979 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.068 |
Times cited |
2 |
Open Access |
Not_Open_Access |
| Notes |
This work was supported by the Hercules Foundation under Grant No. AUHA13009, the Flemish Research Fund (FWO) under Grant No. G.0365.15N, and the Flemish Strategic Initiative for Materials (SIM) under the project InterPoCo. Dr. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). We would like to thank Dr. Hadi Pirgazi from UGent for his technical support to process the ACOM data in the OIM Analysis software. |
Approved |
Most recent IF: 2.068 |
| Call Number |
EMAT @ emat @c:irua:155742 |
Serial |
5135 |
| Permanent link to this record |
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| Author |
Bagherpour, A.; Baral, P.; Colla, M.-S.; Orekhov, A.; Idrissi, H.; Haye, E.; Pardoen, T.; Lucas, S. |
| Title |
Tailoring Mechanical Properties of a-C:H:Cr Coatings |
Type |
A1 Journal Article |
| Year |
2023 |
Publication |
Coatings |
Abbreviated Journal |
Coatings |
| Volume |
13 |
Issue |
12 |
Pages |
2084 |
| Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
| Abstract |
The development of coatings with tunable performances is critical to meet a wide range of technological applications each one with different requirements. Using the plasma-enhanced chemical vapor deposition (PECVD) process, scientists can create hydrogenated amorphous carbon coatings doped with metal (a-C:H:Me) with a broad range of mechanical properties, varying from those resembling polymers to ones resembling diamond. These diverse properties, without clear relations between the different families, make the material selection and optimization difficult but also very rich. An innovative approach is proposed here based on projected performance indices related to fracture energy, strength, and stiffness in order to classify and optimize a-C:H:Me coatings. Four different a-C:H:Cr coatings deposited by PECVD with Ar/C2H2 discharge under different bias voltage and pressures are investigated. A path is found to produce coatings with a selective critical energy release rate between 5–125 J/m2 without compromising yield strength (1.6–2.7 GPa) and elastic limit (≈0.05). Finally, fine-tuned coatings are categorized to meet desired applications under different testing conditions. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
001136013600001 |
Publication Date |
2023-12-14 |
| 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 |
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| ISSN |
2079-6412 |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
Walloon region under the PDR FNRS, C 62/5—PDR/OL 33677636 ; Belgian National Fund for Scientific Research, CDR—J.0113.20 ; National Fund for Scientific Reaserch; |
Approved |
Most recent IF: NA |
| Call Number |
EMAT @ emat @c:irua:202390 |
Serial |
8982 |
| Permanent link to this record |
