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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.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000453254000025 Publication Date 2018-12-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 2 Open Access Not_Open_Access
Notes (up) 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
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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.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001136013600001 Publication Date 2023-12-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2079-6412 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes (up) 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
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Author Idrissi, H.; Samaee, V.; Lumbeeck, G.; Werf, T.; Pardoen, T.; Schryvers, D.; Cordier, P.
Title In Situ Quantitative Tensile Testing of Antigorite in a Transmission Electron Microscope Type A1 Journal article
Year 2020 Publication Journal Of Geophysical Research-Solid Earth Abbreviated Journal J Geophys Res-Sol Ea
Volume 125 Issue 3 Pages
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The determination of the mechanical properties of serpentinites is essential toward the understanding of the mechanics of faulting and subduction. Here we present the first in situ tensile tests on antigorite in a transmission electron microscope. A push‐to‐pull deformation device is used to perform quantitative tensile tests, during which force and displacement are measured, while the evolving microstructure is imaged with the microscope. The experiments have been performed at room temperature on 2 × 1 × 0.2 μm3 beams prepared by focused ion beam. The specimens are not single crystals despite their small sizes. Orientation mapping indicated that several grains were well oriented for plastic slip. However, no dislocation activity has been observed even though the engineering tensile stress went up to 700 MPa. We show also that antigorite does not exhibit a purely elastic‐brittle behavior since, despite the presence of defects, the specimens accumulate permanent deformation and did not fail within the elastic regime. Instead, we observe that strain localizes at grain boundaries. All observations concur to show that under these experimental conditions, grain boundary sliding is the dominant deformation mechanism. This study sheds a new light on the mechanical properties of antigorite and calls for further studies on the structure and properties of grain boundaries in antigorite and more generally in phyllosilicates.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000530895800023 Publication Date 2020-02-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2169-9313 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.9 Times cited Open Access OpenAccess
Notes (up) We thank S. Guillot for having kindly provided us with the two antigorite samples investigated in this study. We acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program under Grant Agreement 787198—TimeMan. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR‐FNRS). We acknowledge fruitful discussions with A. Baronnet. We thank J. Gasc and an anonymous reviewer for their critical comments. Data (movies of the three in situ deformation experiments) can be downloaded (from https://doi.org/10.5281/zenodo.3583135). Approved Most recent IF: 3.9; 2020 IF: 3.35
Call Number EMAT @ emat @c:irua:167594 Serial 6355
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