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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
Permanent link to this record



	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
	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	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	Du, C.; Hoefnagels, J.P.M.; Kolling, S.; Geers, M.G.D.; Sietsma, J.; Petrov, R.; Bliznuk, V.; Koenraad, P.M.; Schryvers, D.; Amin-Ahmadi, B.
	Title	Martensite crystallography and chemistry in dual phase and fully martensitic steels			Type	A1 Journal article
	Year	2018	Publication	Materials characterization	Abbreviated Journal	Mater Charact
	Volume	139	Issue		Pages	411-420
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	Lath martensite is important in industry because it is the key strengthening component in many advanced high strength steels. The study of crystallography and chemistry of lath martensite is extensive in the literature, however, mostly based on fully martensitic steels. In this work, lath martensite in dual phase steels is investigated with a focus on the substructure identification of the martensite islands and microstructural bands using electron backscattered diffraction, and on the influence of the accompanied tempering process during industrial coating process on the distribution of alloying elements using atom probe tomography. Unlike findings for the fully martensitic steels, no martensite islands with all 24 Kurdjumov-Sachs variants have been observed. Almost all martensite islands contain only one main packet with all six variants and minor variants from the remaining three packets of the same prior austenite grain. Similarly, the martensite bands are typically composed of connected domains originating from prior austenite grains, each containing one main packets (mostly with all variants) and few separate variants. The effect of tempering at similar to 450 degrees C (due to the industrial zinc coating process) has also been investigated. The results show a strong carbon partitioning to lath boundaries and Cottrell atmospheres at dislocation core regions due to the thermal process of coating. In contrast, auto-tempering contributes to the carbon redistribution only in a limited manner. The substitutional elements are all homogenously distributed. The phase transformation process has two effects on the material: mechanically, the earlier-formed laths are larger and softer and therefore more ductile (as revealed by nanoindentation); chemically, due to the higher dislocation density inside the later-formed laths, which are generally smaller, carbon Cottrell atmospheres are predominantly observed.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	New York	Editor
	Language		Wos	000431469300044	Publication Date	2018-03-09
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1044-5803	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.714	Times cited		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 2.714
	Call Number	UA @ lucian @ c:irua:151554			Serial	5033
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	Author	Radi, A.; Khalil-Allafi, J.; Etminanfar, M.R.; Pourbabak, S.; Schryvers, D.; Amin-Ahmadi, B.
	Title	Influence of stress aging process on variants of nano-N₄Ti₃precipitates and martensitic transformation temperatures in NiTi shape memory alloy			Type	A1 Journal article
	Year	2018	Publication	Materials & design	Abbreviated Journal	Mater Design
	Volume	262	Issue	262	Pages	74-81
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	In this study, the effect of a stress aging process on the microstructure and martensitic phase transformation of NiTi shape memory alloy has been investigated. NiTi samples were aged at 450 degrees C for 1 h and 5 h under different levels of external tensile stress of 15, 60 and 150 MPa. Transmission electron microscopy (TEM) was used to characterize different variants and morphology of precipitates. The results show that application of all stress levels restricts the formation of precipitates variants in the microstructure after I h stress aging process. However, all variants can be detected by prolonging aging time to 5 h at 15 MPa stress level and the variants formation is again restricted by increasing the stress level. Moreover, the stress aging process resulted in changing the shape of precipitates in comparison with that of the stress-free aged samples. Coffee-bean shaped morphologies were detected for precipitates in all stress levels. According to the Differential Scanning Calorimetry (DSC) results, the martensite start temperature (M-s) on cooling shifts to higher temperatures with increasing the tensile stress during the aging process. This can be related to the change ofaustenite to martensite interface energy due to the different volume fractions and variants of precipitates. (c) 2018 Elsevier Ltd. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos		Publication Date	2018-01-04
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0264-1275	ISBN		Additional Links	UA library record; ; WoS full record; WoS citing articles
	Impact Factor	4.364	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 4.364
	Call Number	UA @ lucian @ c:irua:149854			Serial	4938
Permanent link to this record



	Author	Cao, M.; Xiong, D.-B.; Tan, Z.; Ji, G.; Amin-Ahmadi, B.; Guo, Q.; Fan, G.; Guo, C.; Li, Z.; Zhang, D.
	Title	Aligning graphene in bulk copper : nacre-inspired nanolaminated architecture coupled with in-situ processing for enhanced mechanical properties and high electrical conductivity			Type	A1 Journal article
	Year	2017	Publication	Carbon	Abbreviated Journal
	Volume	117	Issue		Pages	65-74
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Methods used to strengthen metals generally also cause a pronounced decrease in ductility and electrical conductivity. In this work a bioinspired strategy is applied to surmount the dilemma. By assembling copper submicron flakes cladded with in-situ grown graphene, graphene/copper matrix composites with a nanolaminated architecture inspired by a natural nacre have been prepared. Owing to a combined effect-from the bioinspired nanolaminated architecture and improved interfacial bonding, a synergy has been achieved between mechanical strength and ductility as well as electrical conductivity in the graphene/copper matrix composites. With a low volume fraction of only 2.5% of graphene, the composite shows a yield strength and elastic modulus similar to 177% and similar to 25% higher than that of unreinforced copper matrix, respectively, while retains ductility and electrical conductivity comparable to that of pure copper. The bioinspired nanolaminated architecture enhances the efficiencies of two-dimensional (2D) graphene in mechanical strengthening and electrical conducting by aligning graphene to maximize performance for required loading and carrier transporting conditions, and toughens the composites by crack deflection. Meanwhile, in-situ growth of graphene is beneficial for improving interfacial bonding and structural quality of graphene. The strategy sheds light on the development of composites with good combined structural and functional properties. (C) 2017 Elsevier Ltd. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000400212100008	Publication Date	2017-02-27
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0008-6223	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:152635			Serial	7435
Permanent link to this record



	Author	Schouteden, K.; Amin-Ahmadi, B.; Li, Z.; Muzychenko, D.; Schryvers, D.; Van Haesendonck, C.
	Title	Electronically decoupled stacking fault tetrahedra embedded in Au(111) films			Type	A1 Journal article
	Year	2016	Publication	Nature communications	Abbreviated Journal	Nat Commun
	Volume	7	Issue	7	Pages	14001
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	Stacking faults are known as defective structures in crystalline materials that typically lower the structural quality of the material. Here, we show that a particular type of defects, i.e., stacking fault tetrahedra (SFTs), exhibits quantized, particle-in-a-box electronic behaviour, revealing a potential synthetic route to decoupled nanoparticles in metal films. We report on the electronic properties of SFTs that exist in Au(111) films, as evidenced by scanning tunnelling microscopy and confirmed by transmission electron microscopy. We find that the SFTs reveal a remarkable decoupling from their metal surroundings, leading to pronounced energy level quantization effects within the SFTs. The electronic behaviour of the SFTs can be described well by the particle-in-a-box model. Our findings demonstrate that controlled preparation of SFTs may offer an alternative way to achieve well decoupled nanoparticles of high crystalline quality in metal thin films without the need of thin insulating layers.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000390367700001	Publication Date	2016-12-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2041-1723	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	12.124	Times cited	7	Open Access
	Notes	The research in Leuven has been supported by the Research Foundation – Flanders (FWO, Belgium), and by the Flemish Concerted Research Action program (BOF KU Leuven, Project No. GOA/14/007). Z.L. acknowledges the support from the China Scholarship Council (No. 2011624021) and from Internal Funds KU Leuven. K.S. acknowledges additional support from the FWO. The research in Moscow has been supported by grants of the Russian Foundation for Basic Research (RFBR).			Approved	Most recent IF: 12.124
	Call Number	EMAT @ emat @ c:irua:138983			Serial	4336
Permanent link to this record



	Author	Yao, X.; Amin-Ahmadi, B.; Li, Y.; Cao, S.; Ma, X.; Zhang, X.-P.; Schryvers, D.
	Title	Optimization of Automated Crystal Orientation Mapping in a TEM for Ni4Ti3 Precipitation in All-Round SMA			Type	A1 Journal article
	Year	2016	Publication	Shape memory and superelasticity	Abbreviated Journal	Shap Mem Superelasticity
	Volume	2	Issue	2	Pages	286-297
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Automated crystal orientation and phase mapping in TEM are applied to the quantification of Ni4Ti3 precipitates in Ni–Ti shape memory alloys which will be used for the implantation of artificial sphincters operating using the all-round shape memory effect. This paper focuses on the optimization process of the technique to obtain best values for all major parameters in the acquisition of electron diffraction patterns as well as template generation. With the obtained settings, vast statistical data on nano- and microstructures essential to the operation of these shape memory devices become available.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000408743700001	Publication Date	2016-11-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2199-384X	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited	2	Open Access
	Notes	X. Yao gratefully acknowledges the Chinese Scholarship Council (CSC) for providing a PhD scholarship. Research support was also provided by the Key Project of the Natural Science Foundation of Guangdong Province (S2013020012805) and the Natural Science Foundation of China under Grant No. 51401081.			Approved	Most recent IF: NA
	Call Number	EMAT @ emat @ c:irua:138600			Serial	4324
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	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
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	Author	Pardoen, T.; Colla, M.-S.; Idrissi, H.; Amin-Ahmadi, B.; Wang, B.; Schryvers, D.; Bhaskar, U.K.; Raskin, J.-P.
	Title	A versatile lab-on-chip test platform to characterize elementary deformation mechanisms and electromechanical couplings in nanoscopic objects			Type	A1 Journal article
	Year	2016	Publication	Comptes rendus : physique	Abbreviated Journal	Cr Phys
	Volume	17	Issue	17	Pages	485-495
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	A nanomechanical on-chip test platform has recently been developed to deform under a variety of loading conditions freestanding thin films, ribbons and nanowires involving submicron dimensions. The lab-on-chip involves thousands of elementary test structures from which the elastic modulus, strength, strain hardening, fracture, creep properties can be extracted. The technique is amenable to in situ transmission electron microscopy (TEM) investigations to unravel the fundamental underlying deformation and fracture mechanisms that often lead to size-dependent effects in small-scale samples. The method allows addressing electrical and magnetic couplings as well in order to evaluate the impact of large mechanical stress levels on different solid-state physics phenomena. We had the chance to present this technique in details to Jacques Friedel in 2012 who, unsurprisingly, made a series of critical and very relevant suggestions. In the spirit of his legacy, the paper will address both mechanics of materials related phenomena and couplings with solids state physics issues.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000373524300020	Publication Date	2015-12-01
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1631-0705	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.048	Times cited	7	Open Access
	Notes	This research has been performed with the financial support of the “Politique scientifique fédérale” under the framework of the interuniversity attraction poles program, IAP7/21, as well as with the support of the “Communauté française de Belgique” under the program “Actions de recherche concertées” ARC 05/10-330 and ARC Convention No. 11/16-037. The support of the “Fonds belge pour la recherche dans l'industrie et l'agriculture (FRIA)” for M.-S. Colla is also gratefully acknowledged as are the FWO research projects G012012N “Understanding nanocrystalline mechanical behavior from structural investigations” for B. Amin-Ahmadi.			Approved	Most recent IF: 2.048
	Call Number	c:irua:129995			Serial	4014
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	Author	Gong, X.; Marmy, P.; Volodin, A.; Amin-Ahmadi, B.; Qin, L.; Schryvers, D.; Gavrilov, S.; Stergar, E.; Verlinden, B.; Wevers, M.; Seefeldt, M.
	Title	Multiscale investigation of quasi-brittle fracture characteristics in a 9Cr–1Mo ferritic–martensitic steel embrittled by liquid lead–bismuth under low cycle fatigue			Type	A1 Journal article
	Year	2016	Publication	Corrosion science	Abbreviated Journal
	Volume	102	Issue	102	Pages	137-152
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	Liquid metal embrittlement (LME) induced quasi-brittle fracture characteristics of a 9Cr–1Mo ferritic–martensitic steel (T91) after fatigue cracking in lead–bismuth eutectic (LBE) have been investigated at various length scales. The results show that the LME fracture morphology is primarily characterized by quasi-brittle translath flat regions partially covered by nanodimples, shallow secondary cracks propagating along the martensitic lath boundaries as well as tear ridges covered by micro dimples. These diverse LME fracture features likely indicate a LME mechanism involving multiple physical processes, such as weakening induced interatomic decohesion at the crack tip and plastic shearing induced nano/micro voiding in the plastic zone.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000367275700014	Publication Date	2015-10-22
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0010938X	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited	16	Open Access
	Notes	The work is financially supported by the MYRRHA project,SCK•CEN, Belgium and partly funded by the European AtomicEnergy Community’s (Euratom) Seventh Framework ProgrammeFP7/2007-2013 under grant agreement No. 604862 (MatISSEproject) and in the framework of the EERA (European EnergyResearch Alliance) Joint Programme on Nuclear Materials. Dr. TomVan der Donck (KU Leuven) is acknowledged for the EBSD mea-surements. The authors are grateful to Dr. Van Renterghem Wouter(SCK•CEN) for fruitful discussion of the TEM results. Xing Gongsincerely acknowledges valuable suggestions from Dr. S.P. Lynch(Defence Science and Technology Organisation and Monash Uni-versity, Melbourne, Australia).			Approved	Most recent IF: NA
	Call Number	c:irua:129997			Serial	4013
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	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
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	Author	Samani, M.K.; Ding, X.Z.; Khosravian, N.; Amin-Ahmadi, B.; Yi, Y.; Chen, G.; Neyts, E.C.; Bogaerts, A.; Tay, B.K.
	Title	Thermal conductivity of titanium nitride/titanium aluminum nitride multilayer coatings deposited by lateral rotating cathode arc			Type	A1 Journal article
	Year	2015	Publication	Thin solid films : an international journal on the science and technology of thin and thick films	Abbreviated Journal	Thin Solid Films
	Volume	578	Issue	578	Pages	133-138
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	A seriesof [TiN/TiAlN]nmultilayer coatingswith different bilayer numbers n=5, 10, 25, 50, and 100 were deposited on stainless steel substrate AISI 304 by a lateral rotating cathode arc technique in a flowing nitrogen atmosphere. The composition and microstructure of the coatings have been analyzed by using energy dispersive X-ray spectroscopy, X-ray diffraction (XRD), and conventional and high-resolution transmission electron microscopy (HRTEM). XRD analysis shows that the preferential orientation growth along the (111) direction is reduced in the multilayer coatings. TEM analysis reveals that the grain size of the coatings decreases with increasing bilayer number. HRTEMimaging of the multilayer coatings shows a high density misfit dislocation between the TiN and TiAlN layers. The cross-plane thermal conductivity of the coatings was measured by a pulsed photothermal reflectance technique. With increasing bilayer number, the multilayer coatings' thermal conductivity decreases gradually. This reduction of thermal conductivity can be ascribed to increased phonon scattering due to the disruption of columnar structure, reduced preferential orientation, decreased grain size of the coatings and present misfit dislocations at the interfaces.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Lausanne	Editor
	Language		Wos	000351686500019	Publication Date	2015-02-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0040-6090;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.879	Times cited	41	Open Access
	Notes				Approved	Most recent IF: 1.879; 2015 IF: 1.759
	Call Number	c:irua:125517			Serial	3626
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	Author	Colla, M.-S.; Amin-Ahmadi, B.; Idrissi, H.; Malet, L.; Godet, S.; Raskin, J.-P.; Schryvers, D.; Pardoen, T.
	Title	Dislocation-mediated relaxation in nanograined columnar palladium films revealed by on-chip time-resolved HRTEM testing			Type	A1 Journal article
	Year	2015	Publication	Nature communications	Abbreviated Journal	Nat Commun
	Volume	6	Issue	6	Pages	5922
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	The high-rate sensitivity of nanostructured metallic materials demonstrated in the recent literature is related to the predominance of thermally activated deformation mechanisms favoured by a large density of internal interfaces. Here we report time-resolved high-resolution electron transmission microscopy creep tests on thin nanograined films using on-chip nanomechanical testing. Tests are performed on palladium, which exhibited unexpectedly large creep rates at room temperature. Despite the small 30-nm grain size, relaxation is found to be mediated by dislocation mechanisms. The dislocations interact with the growth nanotwins present in the grains, leading to a loss of coherency of twin boundaries. The density of stored dislocations first increases with applied deformation, and then decreases with time to drive additional deformation while no grain boundary mechanism is observed. This fast relaxation constitutes a key issue in the development of various micro- and nanotechnologies such as palladium membranes for hydrogen applications.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000348742300002	Publication Date	2015-01-05
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2041-1723;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	12.124	Times cited	34	Open Access
	Notes	Iap7/21; Fwo G012012n			Approved	Most recent IF: 12.124; 2015 IF: 11.470
	Call Number	c:irua:122045			Serial	731
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	Author	Amin-Ahmadi, B.
	Title	Adanced TEM investigation of the elementary plsticity mechanisms in palladium thin films at the nano scale			Type	Doctoral thesis
	Year	2015	Publication		Abbreviated Journal
	Volume		Issue		Pages
	Keywords	Doctoral thesis; Electron microscopy for materials research (EMAT)
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Antwerpen	Editor
	Language		Wos		Publication Date	0000-00-00
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Additional Links	UA library record
	Impact Factor		Times cited		Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:125236			Serial	56
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	Author	Idrissi, H.; Kobler, A.; Amin-Ahmadi, B.; Coulombier, M.; Galceran, M.; Raskin, J.-P.; Godet, S.; Kuebel, C.; Pardoen, T.; Schryvers, D.
	Title	Plasticity mechanisms in ultrafine grained freestanding aluminum thin films revealed by in-situ transmission electron microscopy nanomechanical testing			Type	A1 Journal article
	Year	2014	Publication	Applied physics letters	Abbreviated Journal	Appl Phys Lett
	Volume	104	Issue	10	Pages	101903
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	In-situ bright field transmission electron microscopy (TEM) nanomechanical tensile testing and in-situ automated crystallographic orientation mapping in TEM were combined to unravel the elementary mechanisms controlling the plasticity of ultrafine grained Aluminum freestanding thin films. The characterizations demonstrate that deformation proceeds with a transition from grain rotation to intragranular dislocation glide and starvation plasticity mechanism at about 1% deformation. The grain rotation is not affected by the character of the grain boundaries. No grain growth or twinning is detected. (C) 2014 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000333082800022	Publication Date	2014-03-12
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951;1077-3118;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.411	Times cited	24	Open Access
	Notes				Approved	Most recent IF: 3.411; 2014 IF: 3.302
	Call Number	UA @ lucian @ c:irua:116866			Serial	2649
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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	Amin-Ahmadi, B.; Idrissi, H.; Galceran, M.; Colla, M.S.; Raskin, J.P.; Pardoen, T.; Godet, S.; Schryvers, D.
	Title	Effect of deposition rate on the microstructure of electron beam evaporated nanocrystalline palladium thin films			Type	A1 Journal article
	Year	2013	Publication	Thin solid films : an international journal on the science and technology of thin and thick films	Abbreviated Journal	Thin Solid Films
	Volume	539	Issue		Pages	145-150
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	The influence of the deposition rate on the formation of growth twins in nanocrystalline Pd films deposited by electron beam evaporation is investigated using transmission electron microscopy. Statistical measurements prove that twin boundary (TB) density and volume fraction of grains containing twins increase with increasing deposition rate. A clear increase of the dislocation density was observed for the highest deposition rate of 5 Å/s, caused by the increase of the internal stress building up during deposition. Based on crystallographic orientation indexation using transmission electron microscopy, it can be concluded that a {111} crystallographic texture increases with increasing deposition rate even though the {101} crystallographic texture remains dominant. Most of the TBs are fully coherent without any residual dislocations. However, for the highest deposition rate (5 Å/s), the coherency of the TBs decreases significantly as a result of the interaction of lattice dislocations emitted during deposition with the growth TBs. The analysis of the grain boundary character of different Pd films shows that an increasing fraction of high angle grain boundaries with misorientation angles around 5565° leads to a higher potential for twin formation.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Lausanne	Editor
	Language		Wos	000321111100025	Publication Date	2013-05-25
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0040-6090;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.879	Times cited	13	Open Access
	Notes	Fwo			Approved	Most recent IF: 1.879; 2013 IF: 1.867
	Call Number	UA @ lucian @ c:irua:109268			Serial	807
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	Author	Wang, X.; Amin-Ahmadi, B.; Schryvers, D.; Verlinden, B.; Van Humbeeck, J.
	Title	Effect of annealing on the transformation behavior and mechanical properties of two nanostructured Ti-50.8at.%Ni thin wires produced by different methods			Type	A1 Journal article
	Year	2013	Publication	Materials science forum	Abbreviated Journal
	Volume	738/739	Issue		Pages	306-310
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	A Ti-50.8at.%Ni wire produced using a co-drawing method and a commercial Ti-50.8at.%Ni wire were annealed at different temperatures between 450°C and 700°C. Grains with diameter less than 100nm were revealed by transmission electron microscopy for both wires before annealing treatment. However, the microstructural heterogeneity of the co-drawn wire is more obvious than that of the commercial wire. Multi-stage martensitic transformation was observed in the co-drawn wire, compared with the one-stage A↔M transformation in the commercial wire after annealing at 600°C for 30min. The differences of total elongation, plateau strain and pseudoelastic recoverable strain between the commercial wire and the co-drawn wire were also observed. The differences of the transformation behavior and mechanical properties between the commercial wire and the co-drawn wire are attributed to the microstructural difference between these two wires.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Lausanne	Editor
	Language		Wos	000316089000055	Publication Date	2013-03-11
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1662-9752;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited	5	Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:104691			Serial	798
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	Author	Amin-Ahmadi, B.; Idrissi, H.; Delmelle, R.; Pardoen, T.; Proost, J.; Schryvers, D.
	Title	High resolution transmission electron microscopy characterization of fcc -> 9R transformation in nanocrystalline palladium films due to hydriding			Type	A1 Journal article
	Year	2013	Publication	Applied physics letters	Abbreviated Journal	Appl Phys Lett
	Volume	102	Issue	7	Pages	071911-71914
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Sputtered nanocrystalline palladium thin films with nanoscale growth twins have been subjected to hydriding cycles. The evolution of the twin boundaries has been investigated using high resolution transmission electron microscopy. Surprisingly, the Sigma 3{112} incoherent twin boundaries dissociate after hydriding into two phase boundaries bounding a 9R phase. This phase which corresponds to single stacking faults located every three {111} planes in the fcc Pd structure was not expected because of the high stacking fault energy of Pd. This observation is connected to the influence of the Hydrogen on the stacking fault energy of palladium and the high compressive stresses building up during hydriding. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793512]
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000315596700023	Publication Date	2013-02-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.411	Times cited	14	Open Access
	Notes	Iap			Approved	Most recent IF: 3.411; 2013 IF: 3.515
	Call Number	UA @ lucian @ c:irua:108303			Serial	1462
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	Author	Peirs, J.; Tirry, W.; Amin-Ahmadi, B.; Coghe, F.; Verleysen, P.; Rabet, L.; Schryvers, D.; Degrieck, J.
	Title	Microstructure of adiabatic shear bands in Ti6Al4V			Type	A1 Journal article
	Year	2013	Publication	Materials characterization	Abbreviated Journal	Mater Charact
	Volume	75	Issue		Pages	79-92
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Microstructural deformation mechanisms in adiabatic shear bands in Ti6Al4V are studied using traditional TEM and selected area diffraction, and more advanced microstructural characterisation techniques such as energy dispersive X-ray spectroscopy, high angle annular dark field STEM and conical dark field TEM. The shear bands under investigation are induced in Ti6Al4V samples by high strain rate compression of cylindrical and hat-shaped specimens in a split Hopkinson pressure bar setup. Samples from experiments interrupted at different levels of deformation are used to study the evolution of the microstructure in and nearby the shear bands. From the early stages of adiabatic shear band formation, TEM revealed strongly elongated equiaxed grains in the shear band. These band-like grains become narrower towards the centre of the band and start to fraction even further along their elongated direction to finally result in a nano-crystalline region in the core. In fully developed shear bands, twins and a needle-like martensite morphology are observed near the shear band.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	New York	Editor
	Language		Wos	000314860900011	Publication Date	2012-11-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1044-5803;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.714	Times cited	56	Open Access
	Notes	Iuap; Fwo			Approved	Most recent IF: 2.714; 2013 IF: 1.925
	Call Number	UA @ lucian @ c:irua:105300			Serial	2065
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	Author	Khalil-Allafi, J.; Amin-Ahmadi, B.
	Title	Effect of mold hardness on microstructure and contraction porosity in ductile cast iron			Type	A1 Journal article
	Year	2011	Publication	Journal of iron and steel research international	Abbreviated Journal	J Iron Steel Res Int
	Volume	18	Issue	4	Pages	44-47
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	The effect of mold hardness on the microstructure of ductile iron and the contraction porosity was investigated. Molds with different hardnesses (0.41, 0.48, 0.55, 0.62 MPa) and a sand mold prepared by Co2 method were used. The influence of silicon content on the induced expansion pressure owing to the formation of graphite was also investigated. The contraction during solidification can be compensated by an induced expansion owing to the graphite relief when the hardness of mold increases; therefore, the possibility of achieving a sound product without using any riser increases.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos		Publication Date	2011-05-01
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1006-706X;	ISBN		Additional Links	UA library record
	Impact Factor	0.836	Times cited	1	Open Access
	Notes				Approved	Most recent IF: 0.836; 2011 IF: 0.213
	Call Number	UA @ lucian @ c:irua:122044			Serial	823
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	Author	Khalil-Allafi, J.; Amin-Ahmadi, B.
	Title	Influence of mold preheating and silicon content on microstructure and casting properties of ductile iron in permanent mold			Type	A1 Journal article
	Year	2011	Publication	Journal of iron and steel research international	Abbreviated Journal	J Iron Steel Res Int
	Volume	18	Issue	3	Pages	34-39
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	The effects of the mold preheating and the silicon content of ductile iron on the percentage of carbides, graphite nodule counts and shrinkage volume were investigated. The results showed that the percentage of carbides and the shrinkage volume decreased when the mold preheating increased. The ductile iron with the carbon equivalent of 4.45% and the silicon content of 2.5% without any porosity defects was achieved when the mold preheating was 450 °C. Increasing the silicon content in the range of 2.1%3.3% led to the increase in graphite nodule count and graphite size and the decrease in percentage of carbides. It is due to the increase in induced expansion pressure during the graphite formation with the increasing of silicon content. The suitable condition for casting a sound product of ductile iron without the riser at the mold preheating temperature of 300 °C is the silicon content of 3.3% and carbon equivalent of 4.7%.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos		Publication Date	2011-03-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1006-706X;	ISBN		Additional Links	UA library record
	Impact Factor	0.836	Times cited	3	Open Access
	Notes				Approved	Most recent IF: 0.836; 2011 IF: 0.213
	Call Number	UA @ lucian @ c:irua:122043			Serial	1629
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	Author	Khalil-Allafi, J.; Amin-Ahmadi, B.
	Title	Multiple-step martensitic transformations in the Ni₅₁Ti₄₉ single crystal			Type	A1 Journal article
	Year	2010	Publication	Journal of materials science	Abbreviated Journal	J Mater Sci
	Volume	45	Issue	23	Pages	6440-6445
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Multiple-step martensitic transformations of an aged Ni51Ti49 single crystal using calorimetric method were investigated. Results show that for short aging times (1045 min) multiple-step martensitic transformations on cooling occur in two steps. Applying intermediate aging times (1.254 h) results in three steps and long aging times (more than 8 h) lead to two-step martensitic transformations again. This behavior has not been recognized in NiTi single crystals in literatures. It can be related to the heterogeneity of composition and stress fields around Ni4Ti3 precipitates.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	London	Editor
	Language		Wos	000282429400021	Publication Date	2010-06-30
	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	5	Open Access
	Notes				Approved	Most recent IF: 2.599; 2010 IF: 1.859
	Call Number	UA @ lucian @ c:irua:122046			Serial	2231
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	Author	Khalil-Allafi, J.; Amin-Ahmadi, B.; Zare, M.
	Title	Biocompatibility and corrosion behavior of the shape memory NiTi alloy in the physiological environments simulated with body fluids for medical applications			Type	A1 Journal article
	Year	2010	Publication	Materials science and engineering: part C: biomimetic materials	Abbreviated Journal	Mat Sci Eng C-Mater
	Volume	30	Issue	8	Pages	1112-1117
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Due to unique properties of NiTi shape memory alloys such as high corrosion resistance, biocompatibility, super elasticity and shape memory behavior, NiTi shape memory alloys are suitable materials for medical applications. Although TiO2 passive layer in these alloys can prevent releasing of nickel to the environment, high nickel content and stability of passive layer in these alloys are very debatable subjects. In this study a NiTi shape memory alloy with nominal composition of 50.7 atom% Ni was investigated by corrosion tests. Electrochemical tests were performed in two physiological environments of Ringer solution and NaCl 0.9% solution. Results indicate that the breakdown potential of the NiTi alloy in NaCl 0.9% solution is higher than that in Ringer solution. The results of Scanning Electron Microscope (SEM) reveal that low pitting corrosion occurred in Ringer solution compared with NaCl solution at potentiostatic tests. The pH value of the solutions increases after the electrochemical tests. The existence of hydride products in the X-ray diffraction analysis confirms the decrease of the concentration of hydrogen ion in solutions. Topographical evaluations show that corrosion products are nearly same in all samples. The biocompatibility tests were performed by reaction of mouse fibroblast cells (L929). The growth and development of cells for different times were measured by numbering the cells or statistics investigations. The figures of cells for different times showed natural growth of cells. The different of the cell numbers between the test specimen and control specimen was negligible; therefore it may be concluded that the NiTi shape memory alloy is not toxic in the physiological environments simulated with body fluids.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Lausanne	Editor
	Language		Wos	000282905600006	Publication Date	2010-06-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0928-4931;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.164	Times cited	34	Open Access
	Notes				Approved	Most recent IF: 4.164; 2010 IF: 2.180
	Call Number	UA @ lucian @ c:irua:122039			Serial	242
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	Author	Amin-Ahmadi, B.; Aashuri, H.
	Title	Semisolid structure for M2 high speed steel prepared by cooling slope			Type	A1 Journal article
	Year	2010	Publication	Journal of materials processing technology	Abbreviated Journal	J Mater Process Tech
	Volume	210	Issue	12	Pages	1632-1635
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Effects of cooling slope angle and the temperature of molten metal on the globular structure of M2 high speed steel after holding at the semisolid state have been investigated. The globular structure was achieved by pouring the molten metal at 1595 °C on the ceramic cooling slope with the length of 200 mm and the angle of 25°. The globular structure of M2 high speed steel in the form of rolledannealed and as cast condition after holding at semisolid state has been achieved. The size of globular grains of cooling slope sample was smaller than that of the rolledannealed and as cast samples. Solid particles of rolledannealed sample after holding at semisolid state had better roundness compared with cooling slope sample. Dissolution of carbides in the austenite phase at grain boundaries leads to formation of globular particles in the semisolid state. MC-type and M6C-type eutectic carbides reprecipitate during cooling cycle along grain boundaries.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000280498200011	Publication Date	2010-06-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0924-0136;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.147	Times cited	12	Open Access
	Notes				Approved	Most recent IF: 3.147; 2010 IF: 1.570
	Call Number	UA @ lucian @ c:irua:122042			Serial	2983
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	Author	Amin-Ahmadi, B.; Aashuri, H.
	Title	Globular structure of M2 high speed steel by thermomechanical treatment in the semisolid state			Type	A1 Journal article
	Year	2010	Publication	Steel research international	Abbreviated Journal	Steel Res Int
	Volume	81	Issue	5	Pages	381-386
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	The globular structure of M2 high speed steel in the rolled – annealed and as cast conditions was investigated in the semisolid state. Metallographic observations resulted in globular austenite particles that were surrounded by a liquid phase. Dissolution of various carbides in the austenite phase at semisolid temperatures led to grain boundary liquation and formation of near-spherical solid grains in a liquid matrix. Therefore, at the semisolid state, the solid particles were free from carbides. MC- type and M6C- type eutectic carbides re- precipitated at the grain boundaries during cooling of the samples from the semisolid temperature. The variation of shape factor versus holding time and holding temperature was examined. A transition value for shape factor changes in high speed steels was achieved. The growth rate constants of the Ostwald ripening and the coalescence mechanisms were calculated by using the experimentally determined rate constant. It was observed that less liquid droplets were enclosed inside the solid particles compared with non-ferrous alloys. Besides, it has been shown that at high solid fraction, the Ostwald ripening mechanism plays a prominent role in the coarsening phenomenon in comparison with the coalescence mechanism. Grains can rotate and arrange low misorientation with each other at high liquid contents, therefore low energetic grain boundaries form between these grains. These grain boundaries play an important role in the coalescence mechanism.
	Address
	Corporate Author				Thesis
	Publisher	Verlag Stahleisen	Place of Publication	Düsseldorf	Editor
	Language		Wos	000278292200007	Publication Date	2010-05-18
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1611-3683;1869-344X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.235	Times cited	1	Open Access
	Notes				Approved	Most recent IF: 1.235; 2010 IF: 0.455
	Call Number	UA @ lucian @ c:irua:122047			Serial	1347
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	Author	Khalil-Allafi, J.; Amin-Ahmadi, B.
	Title	The effect of chemical composition on enthalpy and entropy changes of martensitic transformations in binary NiTi shape memory alloys			Type	P3 Proceeding
	Year	2009	Publication	Journal Of Alloys And Compounds	Abbreviated Journal	J Alloy Compd
	Volume	487	Issue		Pages	363-366
	Keywords	P3 Proceeding; Condensed Matter Theory (CMT)
	Abstract	In the present research work the binary NiTi alloys with various compositions in the range of 50.351 at.% Ni were used. Samples have been annealed at 850 °C for 15 min and then quenched in water. In order to characterize transformation temperatures and enthalpy changes of the forward and the reverse martensitic transformation, Differential Scanning Calorimetric (DSC) experiments were performed. The enthalpy and entropy changes as a function of Ni atomic content have been thermodynamically investigated. Results show that enthalpy and entropy changes of martensitic transformation decrease when Ni atomic content increases. The variation of enthalpy and entropy of martensitic transformation with Ni content in binary NiTi alloys were explained by thermodynamic parameters and electron concentration of alloy (e/a) respectively.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000272521900073	Publication Date	2009-07-31
	Series Editor		Series Title		Abbreviated Series Title	Proceedings of the 22nd International Conference on the Physics of Semiconductors
	Series Volume		Series Issue		Edition
	ISSN	0925-8388;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.133	Times cited	30	Open Access
	Notes				Approved	Most recent IF: 3.133; 2009 IF: 2.135
	Call Number	UA @ lucian @ c:irua:122040			Serial	804
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