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Author Renard, K.; Idrissi, H.; Schryvers, D.; Jacques, P.J.
Title On the stress state dependence of the twinning rate and work hardening in twinning-induced plasticity steels Type A1 Journal article
Year 2012 Publication Scripta materialia Abbreviated Journal Scripta Mater
Volume 66 Issue 12 Pages 966-971
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The influence of the stress state on the twinning rate and work hardening is studied in the case of an FeMnC TWIP steel strained in uniaxial tension, simple shear and rolling. The resulting stressstrain responses exhibit marked differences. The twinning rate, number of activated twinning systems in each grain, twin thickness and transmission of twins across grain boundaries are dependent on the imposed stress state during straining. Relationships between twin features and macroscopic work hardening rate are established.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000304641500004 Publication Date 2012-02-10
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 41 Open Access
Notes Iap Approved Most recent IF: 3.747; 2012 IF: 2.821
Call Number UA @ lucian @ c:irua:98374 Serial 2454
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Author Wang, B.; Idrissi, H.; Shi, H.; Colla, M.S.; Michotte, S.; Raskin, J.P.; Pardoen, T.; Schryvers, D.
Title Texture-dependent twin formation in nanocrystalline thin Pd films Type A1 Journal article
Year 2012 Publication Scripta materialia Abbreviated Journal Scripta Mater
Volume 66 Issue 11 Pages 866-871
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Nanocrystalline Pd films were produced by electron-beam evaporation and sputter deposition. The electron-beam-evaporated films reveal randomly oriented nanograins with a relatively high density of growth twins, unexpected in view of the high stacking fault energy of Pd. In contrast, sputter-deposited films show a clear 〈1 1 1〉 crystallographic textured nanostructure without twins. These results provide insightful information to guide the generation of microstructures with enhanced strength/ductility balance in high stacking fault energy nanocrystalline metallic thin films.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000303621900007 Publication Date 2012-01-31
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 19 Open Access
Notes Iap; Fwo Approved Most recent IF: 3.747; 2012 IF: 2.821
Call Number UA @ lucian @ c:irua:96955 Serial 3566
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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
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Author Idrissi, H.; Ryelandt, L.; Veron, M.; Schryvers, D.; Jacques, P.J.
Title Is there a relationship between the stacking fault character and the activated mode of plasticity of FeMn-based austenitic steels? Type A1 Journal article
Year 2009 Publication Scripta materialia Abbreviated Journal Scripta Mater
Volume 60 Issue 11 Pages 941-944
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract By changing the testing temperature, an austenitic FeMnAlSi alloy presents either å-martensite transformation or mechanical twinning during straining. In order to understand the nucleation and growth mechanisms involved in both phenomena, defects and particularly stacking faults, were characterized by transmission electron microscopy. It is observed that the character of the stacking faults also changes (from extrinsic to intrinsic) together with the temperature and the activated mode of plasticity.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000265359900005 Publication Date 2009-02-10
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 84 Open Access
Notes Iap Approved Most recent IF: 3.747; 2009 IF: 2.949
Call Number UA @ lucian @ c:irua:77276 Serial 1751
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Author Lezaack, M.B.; Hannard, F.; Zhao, L.; Orekhov, A.; Adrien, J.; Miettinen, A.; Idrissi, H.; Simar, A.
Title Towards ductilization of high strength 7XXX aluminium alloys via microstructural modifications obtained by friction stir processing and heat treatments Type A1 Journal article
Year 2021 Publication Materialia Abbreviated Journal
Volume 20 Issue Pages 101248
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract High strength 7XXX aluminium series reach exceptional strength, higher than all other industrial aluminium alloys. However, they suffer from a lack of ductility compared to softer series. This work presents a procedure to improve the ductility of 7475 Al alloy in high strength condition, reaching a true fracture strain of 70% at full 500 MPa T6 yield strength. Using friction stir processing (FSP) and post-FSP heat treatments, 100% of industrial rolled material T6 yield stress is maintained but a 180% increase in fracture strain is measured for the processed material. This ductility improvement is studied by in-situ synchrotron X-ray tomography and is explained by the reduction of intermetallic particles size and the homogenization of their spatial distribution. Furthermore, the microstructure after FSP shows equiaxed refined grains which favour crack deviation as opposed to large cracks parallel to the elongated coarse grains in rolled plate. These results are paving the way to better formability and crashworthiness of 7XXX alloys.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000718127100006 Publication Date 2021-10-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2589-1529 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:184145 Serial 6894
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Author Marteleur, M.; Idrissi, H.; Amin-Ahmadi, B.; Prima, F.; Schryvers, D.; Jacques, P.J.
Title On the nucleation mechanism of {112} < 111 > mechanical twins in as-quenched beta metastable Ti-12 wt.% Mo alloy Type A1 Journal article
Year 2019 Publication Materialia Abbreviated Journal
Volume 7 Issue Pages Unsp 100418
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Recently developed beta-metastable Ti grades take advantage of the simultaneous activation of TRIP and TWIP effects for enhancing their work hardening rate. However, the role of each plasticity mechanism on the macroscopic mechanical response is still unclear. In this work, the nucleation mechanism of the first activated plasticity mechanism, namely {112} < 111 > twinning, was investigated. Firstly, post-mortem TEM analysis showed that twins nucleate on pre-existing microstructural defects such as thermal jogs with the zonal dislocation mechanism. The precipitation of the omega phase on twin boundaries has been observed, as well as the emission of numerous dislocations from super-jogs present in these twin boundaries. It is also shown that {112} < 111 > twins act as effective dislocation sources for the subsequent plasticity mechanisms such as beta -> alpha '' martensitic transformation and {332} < 111 > twinning. Secondly, in situ TEM tensile testing of the investigated Ti grade highlighted the primary role of the initial defect configuration present in the microstructure. It is shown that twins cannot nucleate without the presence of specific defects allowing the triggering of the dislocation decomposition needed for the twinning mechanism highlighted in investigated bulk samples.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000537131000052 Publication Date 2019-07-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2589-1529 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:170326 Serial 6875
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Author Zhao, L.; Macias, J.G.S.; Ding, L.; Idrissi, H.; Simar, A.
Title Damage mechanisms in selective laser melted AlSi10Mg under as built and different post-treatment conditions Type A1 Journal article
Year 2019 Publication Microstructure And Processing Abbreviated Journal Mat Sci Eng A-Struct
Volume 764 Issue 764 Pages 138210
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Selective laser melting (SLM) manufactured AlSi10Mg alloys present a fine silicon-rich network and precipitates which grant high mechanical strength but low ductility. Post-treatments, aiming at eliminating inherent defects related to SLM such as residual stresses, porosity or inhomogeneity, result in significant changes in the microstructure and impact both the hardening and the damage mechanisms of the post-treated material. The present work is dedicated to the investigation of the fracture of SLM AlSi10Mg under as built and three post-treatment conditions, namely two stress relieve heat treatments and friction stir processing (FSP). It is found that the interconnected Si network fosters damage at low strain due to the brittleness of the Si phase. The onset of damage transfers load to the enclosed Al phase which then fractures quickly under high stress, thus leading to low material ductility. In contrast, when the Si network is globularized into Si particles, the ductility is highly increased even in the case where the porosity and inhomogeneity of the microstructure remain after the post-treatment. The ductility enhancement results from the delay in void nucleation on the Si particles as well as from the tolerance for void growth in the Al matrix.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000486360100029 Publication Date 2019-07-27
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 1 Open Access
Notes ; This research work has been supported by the WALInnov LongLifeAM project, Convention n 1810016, funded by Service public de Wallonie Economic Emploi Recherche (SPW-EER). L. Ding and A. Simar acknowledge the financial support of the European Research Council (ERC) for the Starting Grant ALUFIX project (grant agreement n 716678). J. G. Santos Macias acknowledges the support of the Fonds de la recherche scientifique -FNRS (FRIA grant), Belgium. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSRFNRS). Any-Shape is acknowledged for material supply. We thank Prof. P. J. Jacques from UCLouvain for fruitful discussion and critical reading of the paper. ; Approved Most recent IF: 3.094
Call Number UA @ admin @ c:irua:162800 Serial 5386
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Author Boulay, E.; Ragoen, C.; Idrissi, H.; Schryvers, D.; Godet, S.
Title Influence of amorphous phase separation on the crystallization behavior of glass-ceramics in the BaO-TiO2-SiO2 system Type A1 Journal article
Year 2014 Publication Journal of non-crystalline solids Abbreviated Journal J Non-Cryst Solids
Volume 384 Issue Pages 61-72
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The possible role of a prior amorphous phase separation on the subsequent crystallization has been the topic of vigorous debates over the last decades and has not yet been clarified, especially regarding the role of the interfaces created by the phase separation. This study proposes to focus on the interplay between a prior amorphous phase separation and the crystallization of fresnoite in the BaO-TiO2-SiO2 system. The crystallization behavior of a non-stoichiometric composition inside the miscibility gap (called APS) is compared with the stoichiometric composition (called FRES) and a non-stoichiometric composition outside the miscibility gap (called NoAPS). The crystallization mechanisms are compared using differential thermal analysis (DTA) by calculating the Avrami parameters and the activation energies as a function of the particle size. The DTA study shows that the two non-stoichiometric compositions exhibit a pronounced surface crystallization behavior whereas FRES undergoes bulk nucleation. This is supported by a multi-scale microstructure characterization. Furthermore, this study demonstrates that the amorphous phase separation and the associated interfaces do not play any significant role in the nucleation step. Moreover, transmission electron microscope (TEM) and local orientation measurements show that the growth of the dendrites is not hindered by the SiO2-rich droplets. The final stage of crystallization of APS is tentatively explained by two composition effects that must be further investigated: the viscosity effect and the formation of a eutectic. (C) 2013 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000329422400010 Publication Date 2013-07-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3093; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.124 Times cited 10 Open Access
Notes Approved Most recent IF: 2.124; 2014 IF: 1.766
Call Number UA @ lucian @ c:irua:114782 Serial 1614
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Author Wang, B.; Idrissi, H.; Galceran, M.; Colla, M.S.; Turner, S.; Hui, S.; Raskin, J.P.; Pardoen, T.; Godet, S.; Schryvers, D.
Title Advanced TEM investigation of the plasticity mechanisms in nanocrystalline freestanding palladium films with nanoscale twins Type A1 Journal article
Year 2012 Publication International journal of plasticity Abbreviated Journal Int J Plasticity
Volume 37 Issue Pages 140-156
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Nanocrystalline palladium thin films deposited by electron-beam evaporation and deformed by on-chip tensile testing reveal a surprisingly large strain hardening capacity when considering the small similar to 25 nm grain size. The as-grown films contain several coherent single and multifold twin boundaries. The coherency of the twin boundaries considerably decreases with deformation due to dislocation/twin boundary interactions. These reactions are described based on a detailed analysis of the number and the type of dislocations located at the twin boundaries using high-resolution TEM, including aberration corrected microscopy. Sessile Frank dislocations were observed at the twin/matrix interfaces, explaining the loss of the TB coherency due to the Burgers vector pointing out of the twinning plane. Grain boundary mediated processes were excluded as a mechanism dominating the plastic deformation based on the investigation of the grain size distribution as well as the crystallographic texture using Automated Crystallographic Orientation Indexation TEM. Other factors influencing the plastic deformation such as impurities and the presence of a native passivation oxide layer at the surface of the films were investigated using analytical TEM. The twin boundaries observed in the present work partly explain the high strain hardening capacity by providing both increasing resistance to dislocation motion with deformation and a source for dislocation multiplication. (C) 2012 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000307416100009 Publication Date 2012-05-16
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 44 Open Access
Notes Iap; Fwo Approved Most recent IF: 5.702; 2012 IF: 4.356
Call Number UA @ lucian @ c:irua:101082 Serial 74
Permanent link to this record
 

 
Author Delvaux, A.; Lumbeeck, G.; Idrissi, H.; Proost, J.
Title Effect of microstructure and internal stress on hydrogen absorption into Ni thin film electrodes during alkaline water electrolysis Type A1 Journal article
Year 2020 Publication Electrochimica Acta Abbreviated Journal Electrochim Acta
Volume 340 Issue Pages 135970-10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Efforts to improve the cell efficiency of hydrogen production by water electrolysis continue to address the electrochemical kinetics of the oxygen and hydrogen evolution reactions in detail. The objective of this work is to study a parasitic reaction occurring during the hydrogen evolution reaction (HER), namely the absorption of hydrogen atoms into the bulk electrode. Effects of the electrode microstructure and internal stress on this reaction have been addressed as well in this paper. Ni thin film samples were deposited on a Si substrate by sputter deposition with different deposition pressures, resulting in different microstructures and varying levels of internal stress. These microstructures were first analyzed in detail by Transmission Electron Microscopy (TEM). Cathodic chrono-amperometric measurements and cyclic voltammetries have then been performed in a homemade electrochemical cell. These tests were coupled to a multi-beam optical sensor (MOS) in order to obtain in-situ curvature measurements during hydrogen absorption. Indeed, since hydrogen absorption in the thin film geometry results in a constrained volume expansion, internal stress generation during HER can be monitored by means of curvature measurements. Our results show that different levels of internal stress, grain size and twin boundary density can be obtained by varying the deposition parameters. From an electrochemical point of view, this paper highlights the fact that the electrochemical surface mechanisms during HER are the same for all the electrodes, regardless of their microstructure. However it is shown that the absolute amount of hydrogen being absorbed into the Ni thin films increases when the grain size is reduced, due to a higher grain boundaries density which are favourite absorption sites for hydrogen. At the same time, it was concluded that H-2 evolution is favoured at electrodes having a more compressive (i.e. a less tensile) internal stress. Finally, the subtle effect of microstructure on the hydrogen absorption rate will be discussed as well. (C) 2020 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000521531800011 Publication Date 2020-02-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-4686 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.6 Times cited 2 Open Access Not_Open_Access
Notes ; The authors gratefully acknowledge financial support of the Public Service of Wallonia e Department of Energy and Sustainable Building, through the project WallonHY. The ACOM-TEM work was supported by the Hercules Foundation [Grant No. AUHA13009], the Flemish Research Fund (FWO) [Grant No. G.0365.15 N], and the Flemish Strategic Initiative for Materials (SIM) under the project InterPoCo. We also like to cordially thank Ronny Santoro for carrying out the ICP-OES measurements. ; Approved Most recent IF: 6.6; 2020 IF: 4.798
Call Number UA @ admin @ c:irua:168536 Serial 6497
Permanent link to this record
 

 
Author Boulay, E.; Nakano, J.; Turner, S.; Idrissi, H.; Schryvers, D.; Godet, S.
Title Critical assessments and thermodynamic modeling of BaO-SiO2 and SiO2-TiO2 systems and their extensions into liquid immiscibility in the BaO-SiO2-TiO2 system Type A1 Journal article
Year 2014 Publication Calphad computer coupling of phase diagrams and thermochemistry Abbreviated Journal Calphad
Volume 47 Issue Pages 68-82
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract This study discusses rational reproduction of liquid immiscibility in the BaO-SiO2-TiO2 system. While a ternary assessment requires sub-binary descriptions in the same thermodynamic model, the related sub-binary systems BaO-SiO2, BaO-TiO2 and SiO2-TiO2 liquid and solid phases have been evaluated using different thermodynamic models in the literature. In this study, BaO-SiO2 and SiO2-TiO2 were assessed using the Ionic Two Sublattice model (I2SL) based on experimental data from the literature. BaO-TiO2 was already assessed using this model. Binary descriptions developed were then used for the assessment of liquid immiscibility in the BaO-SiO2-TiO2 system. Ternary interaction parameters were found necessary for rational reproduction of the new ternary experimental data gathered in the present work. The model parameters for each system were evaluated using a CAPLHAD approach. A set of parameters is proposed. They show good agreement between the calculated and experimental equilibrium liquidus, liquid immiscibility and thermochemical properties in the BaO-SiO2-TiO2 system. (C) 2014 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000346224700008 Publication Date 2014-07-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0364-5916; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.6 Times cited 9 Open Access
Notes Approved Most recent IF: 1.6; 2014 IF: 1.370
Call Number UA @ lucian @ c:irua:122776 Serial 540
Permanent link to this record
 

 
Author Fu, Y.; Ding, L.; Singleton, M.L.; Idrissi, H.; Hermans, S.
Title Synergistic effects altering reaction pathways : the case of glucose hydrogenation over Fe-Ni catalysts Type A1 Journal article
Year 2021 Publication Applied Catalysis B-Environmental Abbreviated Journal Appl Catal B-Environ
Volume 288 Issue Pages 119997
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Carbon black (CB) supported Ni, Fe, or Fe-Ni alloy catalysts were synthesized by sol-gel to elucidate the reaction pathways over each catalyst, as well as synergistic effects in glucose to sorbitol hydrogenation. The bimetallic materials presented small and alloyed nanoparticles that were richer in reduced metallic sites at the surface than their monometallic counterparts. Glucose isomerization to fructose was favoured over Fe/CB, while glucose hydrogenation to sorbitol is the dominating pathway over Ni/CB catalyst. By contrast, sorbitol production was promoted and undesired isomerization was suppressed when Fe and Ni formed a nanoalloy. In addition, the alloy catalyst presented better stability than the corresponding monometallic catalyst. A comparison with a mechanical mixture of Fe/CB and Ni/CB monometallic catalysts demonstrated the synergy at the nanoscale in the alloy. By comparing different Fe:Ni ratios, the 1:1 formulation was identified as the best compromise to achieve a high activity while maintaining high sorbitol selectivity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000632996500002 Publication Date 2021-02-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0926-3373 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.446 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 9.446
Call Number UA @ admin @ c:irua:177621 Serial 6789
Permanent link to this record
 

 
Author Arseenko, M.; Hannard, F.; Ding, L.; Zhao, L.; Maire, E.; Villanova, J.; Idrissi, H.; Simar, A.
Title A new healing strategy for metals : programmed damage and repair Type A1 Journal article
Year 2022 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 238 Issue Pages 118241-10
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Self-healing strategies aim at avoiding part repair or even replacement, which is time consuming, expen-sive and generates waste. However, strategies for metallic systems are still under-developed and solid-state solutions for room temperature service are limited to nano-scale damage repair. Here we propose a new healing strategy of micron-sized damage requiring only short and low temperature heating. This new strategy is based on damage localization particles, which can be healed by fast diffusing atoms of the matrix activated during heat treatment. The healing concept was successfully validated with a com-mercial aluminum alloy and manufactured by Friction Stir Processing (FSP). Damage was demonstrated to initiate on particles that were added to the matrix during material processing. In situ 2D and 3D nano -imaging confirmed healing of the damaged material and showed that heating this material for 10 min at 400 degrees C is sufficient to heal incipient damage with complete filling of 70% of all damage (and up to 90% when their initial size is below 0.2 mu m). Furthermore, strength is retained and the work of fracture of the alloy is improved by about 40% after healing. The proposed Programmed Damage and Repair healing strategy could be extended to other metal based systems presenting precipitation. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000843502700006 Publication Date 2022-08-03
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 9.4 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 9.4
Call Number UA @ admin @ c:irua:190561 Serial 7121
Permanent link to this record
 

 
Author Lemoine, G.; Delannay, L.; Idrissi, H.; Colla, M.-S.; Pardoen, T.
Title Dislocation and back stress dominated viscoplasticity in freestanding sub-micron Pd films Type A1 Journal article
Year 2016 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 111 Issue 111 Pages 10-21
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A dislocation-based crystal plasticity model is developed in order to study the mechanical and creep/ relaxation behaviour of polycrystalline metallic thin films. The model accounts for the confinement of plasticity due to grain boundaries and for the anisotropy of individual grains, as well as for the significant viscoplastic effects associated to dislocation dominated thermally activated mechanisms. Numerical predictions are assessed based on experimental tensile test followed by relaxation on freestanding Pd films, based on an on-chip test technique. The dislocation-based mechanism assumption captures all the experimental trends, including the stress strain response, the relaxation behaviour and the dislocation density evolution, confirming the dominance of a dislocation driven deformation mechanism for the present Pd films with high defects density. The model has also been used to address some original experimental evidences involving back stresses, Bauschinger effect, backward creep and strain recovery. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000375812100002 Publication Date 2016-03-26
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 6 Open Access
Notes Approved Most recent IF: 5.301
Call Number UA @ lucian @ c:irua:133636 Serial 4162
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
Corporate Author Thesis
Publisher 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
 

 
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 Renard, K.; Idrissi, H.; Schryvers, D.; Jacques, P.J.
Title Multiscale characterization of the work hardening mechanisms in Fe-Mn based TWIP steels Type A1 Journal article
Year 2012 Publication Steel research international Abbreviated Journal Steel Res Int
Volume 83 Issue 4 Pages 385-390
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract When strained in tension, high-manganese austenitic twinning induced plasticity (TWIP) steels achieve very high strength and elongation before necking. The main hypotheses available in the literature about the origin of their excellent work hardening include deformation twinning and dynamic strain ageing. In order to provide some answers, various experiments at different scales were conducted on FeMnC steels and the Fe28 wt%Mn3.5 wt%Al2.8 wt%Si alloy. At a macroscopic scale, tensile tests were performed on all the studied grades. It was shown that, though the FeMnAlSi based alloy retains very high elongation, the FeMnC steels properties are even more extraordinary. Tensile tests at different strain rates with the help of digital image correlation were also performed on the Fe20 wt%Mn1.2 wt%C steel to study the PLC effect occurring in this type of steel. It is suggested that supplementary hardening could come from reorientation of MnC pairs in the cores of the dislocations. At a microscopic scale, the Fe20 wt%Mn1.2 wt%C TWIP steel and the FeMnAlSi grade were thoroughly investigated by means of in situ TEM analysis. In the FeMnC steel, the formed twins could also lead to a composite effect, since they contain plenty of sessile dislocations. In the FeMnAlSi alloy, mechanical twins are thicker and contain fewer defects, leading to a lower work hardening than the other grade.
Address
Corporate Author Thesis
Publisher Verlag Stahleisen Place of Publication Düsseldorf Editor
Language Wos 000302471600016 Publication Date 2012-02-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1611-3683; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.235 Times cited 12 Open Access
Notes Approved Most recent IF: 1.235; 2012 IF: 0.493
Call Number UA @ lucian @ c:irua:97391 Serial 2239
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Author Idrissi, H.; Amin-Ahmadi, B.; Wang, B.; Schryvers, D.
Title Review on TEM analysis of growth twins in nanocrystalline palladium thin films : toward better understanding of twin-related mechanisms in high stacking fault energy metals Type A1 Journal article
Year 2014 Publication Physica status solidi: B: basic research Abbreviated Journal Phys Status Solidi B
Volume 251 Issue 6 Pages 1111-1124
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Various modes of transmission electron microscopy including aberration corrected imaging were used in order to unravel the fundamental mechanisms controlling the formation of growth twins and the evolution of twin boundaries under mechanical and hydrogen loading modes in nanocrystalline (nc) palladium thin films. The latter were produced by electron-beam evaporation and sputter deposition and subjected to uniaxial tensile deformation as well as hydriding/dehydriding cycles. The results show that the twins form by dissociation of grain boundaries. The coherency of Σ3{111} coherent twin boundaries considerably decreases with deformation due to dislocation/twin boundary interactions while Σ3{112} incoherent twin boundaries dissociate under hydrogen cycling into two-phase boundaries bounding a new and unstable 9R phase. The effect of these elementary mechanisms on the macroscopic behavior of the palladium films is discussed and compared to recent experimental and simulation works in the literature. The results provide insightful information to guide the production of well-controlled population of growth twins in high stacking fault energy nc metallic thin films. The results also indicate directions for further enhancement of the mechanical properties of palladium films as needed for instance in palladium-based membranes in hydrogen applications.
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000337608600001 Publication Date 2014-02-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-1972; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.674 Times cited 7 Open Access
Notes Iap P7/21; Fwo G012012n Approved Most recent IF: 1.674; 2014 IF: 1.489
Call Number UA @ lucian @ c:irua:114580 Serial 2905
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Author Proost, J.; Blaffart, F.; Turner, S.; Idrissi, H.
Title On the Origin of Damped Electrochemical Oscillations at Silicon Anodes (Revisited) Type A1 Journal article
Year 2014 Publication ChemPhysChem : a European journal of chemical physics and physical chemistry Abbreviated Journal Chemphyschem
Volume 15 Issue 14 Pages 3116-3124
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Electrochemical oscillations accompanying the formation of anodic silica have been shown in the past to be correlated with rather abrupt changes in the mechanical stress state of the silica film, commonly associated with some kind of fracture or porosification of the oxide. To advance the understanding on the origin of such oscillations in fluoride-free electrolytes, we have revisited a seminal experiment reported by Lehmann almost two decades ago. We thereby demonstrate that the oscillations are not stress-induced, and do not originate from a morphological transformation of the oxide in the course of anodisation. Alternatively, the mechanical features accompanying the oscillations can be explained by a partial relaxation of the field-induced electrostrictive stress. Furthermore, our observations suggest that the oscillation mechanism more likely results from a periodic depolarisation of the anodic silica.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000342770500029 Publication Date 2014-08-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1439-4235; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.075 Times cited 5 Open Access
Notes Approved Most recent IF: 3.075; 2014 IF: 3.419
Call Number UA @ lucian @ c:irua:121086 Serial 2444
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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
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Author Idrissi, H.; Schryvers, D.
Title Investigation of the elementary mechanisms controlling dislocation/twin boundary interactions in fcc metals and alloys : from conventional to advanced TEM characterization Type H2 Book chapter
Year 2012 Publication Abbreviated Journal
Volume Issue Pages 1213-1224
Keywords H2 Book chapter; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Formatex Research Center Place of Publication S.l. Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-84-939843-6-6 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:104694 Serial 1737
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