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Author Cao, S.; Nishida, M.; Schryvers, D.
Title Quantitative three-dimensional analysis of Ni4Ti3 precipitate morphology and distribution in polycrystalline Ni-Ti Type A1 Journal article
Year 2011 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 59 Issue 4 Pages 1780-1789
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The three-dimensional size, morphology and distribution of Ni4Ti3 precipitates in a Ni50.8Ti49.2 polycrystalline shape memory alloy with a heterogeneous microstructure have been investigated using a focused ion beam/scanning electron microscopy slice-and-view procedure. The mean volume, central plane diameter, thickness, aspect ratio and sphericity of the precipitates in the grain interior as well as near to the grain boundary were measured and/or calculated. The morphology of the precipitates was quantified by determining the equivalent ellipsoids with the same moments of inertia and classified according to the Zingg scheme. Also, the pair distribution functions describing the three-dimensional distributions were obtained from the coordinates of the precipitate mass centres. Based on this new data it is suggested that the existence of the heterogeneous microstructure could be due to a very small concentration gradient in the grains of the homogenized material and that the resulting multistage martensitic transformation originates in strain effects related to the size of the precipitates and scale differences of the available B2 matrix in between the precipitates.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000287265100045 Publication Date 2010-12-20
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 34 Open Access (down)
Notes Fwo Approved Most recent IF: 5.301; 2011 IF: 3.755
Call Number UA @ lucian @ c:irua:85533 Serial 2766
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Author Shi, H.; Frenzel, J.; Martinez, G.T.; Van Rompaey, S.; Bakulin, A.; Kulkova, A.; Van Aert, S.; Schryvers, D.
Title Site occupation of Nb atoms in ternary Ni-Ti-Nb shape memory alloys Type A1 Journal article
Year 2014 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 74 Issue Pages 85-95
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Nb occupancy in the austenite B2-NiTi matrix and Ti2Ni phase in NiTiNb shape memory alloys was investigated by aberration-corrected scanning transmission electron microscopy and precession electron diffraction. In both cases, Nb atoms were found to prefer to occupy the Ti rather than Ni sites. A projector augmented wave method within density functional theory was used to calculate the atomic and electronic structures of the austenitic B2-NiTi matrix phase and the Ti2Ni precipitates both with and without addition of Nb. The obtained formation energies and analysis of structural and electronic characteristics explain the preference for Ti sites for Nb over Ni sites.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000338621400009 Publication Date 2014-05-08
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 21 Open Access (down)
Notes Approved Most recent IF: 5.301; 2014 IF: 4.465
Call Number UA @ lucian @ c:irua:118334 Serial 3028
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Author Seo, J.W.; Schryvers, D.
Title TEM investigation of the microstructure and defects of CuZr martensite: 1: morphology and twin systems Type A1 Journal article
Year 1998 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 46 Issue Pages 1165-1175
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000072289100009 Publication Date 2002-07-25
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 46 Open Access (down)
Notes Approved Most recent IF: 5.301; 1998 IF: 1.834
Call Number UA @ lucian @ c:irua:48360 Serial 3479
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Author Seo, J.W.; Schryvers, D.
Title TEM investigation of the microstructure and defects of CuZr martensite: 2: planar defects Type A1 Journal article
Year 1998 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 46 Issue Pages 1177-1183
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000072289100010 Publication Date 2002-07-25
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 21 Open Access (down)
Notes Approved Most recent IF: 5.301; 1998 IF: 1.834
Call Number UA @ lucian @ c:irua:48361 Serial 3480
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Author Chen, X.; Cao, S.; Ikeda, T.; Srivastava, V.; Snyder, G.J.; Schryvers, D.; James, R.D.
Title A weak compatibility condition for precipitation with application to the microstructure of PbTe-Sb2Te3 thermoelectrics Type A1 Journal article
Year 2011 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 59 Issue 15 Pages 6124-6132
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract We propose a weak condition of compatibility between phases applicable to cases exhibiting full or partial coherence and Widmanstätten microstructure. The condition is applied to the study of Sb2Te3 precipitates in a PbTe matrix in a thermoelectric alloy. The weak condition of compatibility predicts elongated precipitates lying on a cone determined by a transformation stretch tensor. Comparison of this cone with the long directions of precipitates determined by a slice-and-view method of scanning electron microscopy combined with focused ion beam sectioning shows good agreement between theory and experiment. A further study of the morphology of precipitates by the Eshelby method suggests that interfacial energy also plays a role and gives an approximate value of interfacial energy per unit area of 250 dyn cm−1.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000294086900026 Publication Date 2011-07-22
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 8 Open Access (down)
Notes Approved Most recent IF: 5.301; 2011 IF: 3.755
Call Number UA @ lucian @ c:irua:92388 Serial 3911
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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 (down)
Notes Approved Most recent IF: 5.301
Call Number UA @ lucian @ c:irua:133636 Serial 4162
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Author Zhang, Z.; Rosalie, J.M.; Medhekar, N.V.; Bourgeois, L.
Title Resolving the FCC/HCP interfaces of the \gamma'(Ag2Al) precipitate phase in aluminium Type A1 Journal article
Year 2019 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 174 Issue 174 Pages 116-130
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The gamma'(Ag2Al) phase in the Al-Ag alloy system has served as a textbook example for understanding phase transformations, precipitating hexagonal close-packed (HCP) crystals in the face-centred cubic (FCC) aluminium matrix. The gamma' precipitates display fully coherent interfaces at their broad facets and semicoherent interfaces at their edges. Shockley partial dislocations are expected to decorate the semicoherent interface due to the FCC-HCP structural transformation. Determining the exact locations and core structures of interfacial dislocations, however, remains challenging. In this study, we used aberration-corrected scanning transmission electron microscopy and atomistic simulations to re-visit this classical system. We characterised and explained the Ag segregation at coherent interfaces in the early stage of precipitation. For semicoherent interfaces, interfacial dislocations and reconstructions were revealed by bridging advanced microstructure characterisation and atomistic simulations. In particular, we discovered a new FCC/HCP interfacial structure that displays a unique combination of Shockley partial, Lomer-Cottrell and Hirth dislocations that evolve from the known interfacial structure purely composed by Shockley partial dislocations. Our findings show that the FCC-HCP transformation is more complex than hitherto considered, due to the interplay between structure and composition confined at interfaces. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000474501300011 Publication Date 2019-05-18
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 3 Open Access (down)
Notes ; The authors acknowledge funding from the Australian Research Council (LE0454166, LE110100223), the Victorian State Government and Monash University for instrumentation, and use of the facilities within the Monash Centre for Electron Microscopy. LB and NM acknowledge the financial support of the Australian Research Council (DP150100558). The authors also gratefully acknowledge the computational support from Monash Advanced Research Computing Hybrid, the National Computational Infrastructure and Pawsey Supercomputing Centre. ZZ is thankful to Monash University for a Monash Graduate Scholarship, a Monash International Postgraduate Research Scholarship and a Monash Centre for Electron Microscopy Postgraduate Scholarship. ZZ is indebted to Matthew Weyland for his training in aberration-corrected electron microscopy, Scott Findlay for his help on image simulations, Xiang Gao for alloy casting and Ian Polmear for discussions. ; Approved Most recent IF: 5.301
Call Number UA @ admin @ c:irua:161192 Serial 5395
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Author Weng, Y.; Ding, L.; Zhang, Z.; Jia, Z.; Wen, B.; Liu, Y.; Muraishi, S.; Li, Y.; Liu, Q.
Title Effect of Ag addition on the precipitation evolution and interfacial segregation for Al-Mg-Si alloy Type A1 Journal article
Year 2019 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 180 Issue 180 Pages 301-316
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The effect of Ag addition on the precipitation evolution and interfacial segregation for Al-Mg-Si alloys was systematically investigated by atomic resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), atom probe tomography (APT) and density functional theory (DFT) calculation. At the early aging stage, Ag atoms could enter clusters and refine the distribution of these clusters. Then, Ag atoms preferentially segregate at the GP zone/alpha-Al and beta ''/alpha-Al interfaces at the peak aging stage by the replacement of Al atoms in FCC matrix. With prolonging aging time, Ag atoms generally incorporate into the interior of beta '' precipitate, facilitating the formation of QP lattice (a hexagonal network of Si atomic columns) and the local symmetry substructures, Ag sub-unit (1) and Ag sub-unit (2). At the over-aged stage, the Ag sub-unit (1) and Ag sub-unit (2) could transform to the beta'(Ag) (i.e. beta'(Ag1) and beta'(Ag2).) and Q'(Ag) unit cells, respectively. All the precipitates at the over-aging stage have a composite and disordered structure due to the coexistence of different unit cells (beta'(Ag1), beta'(Ag2), Q'(Ag) and beta') and the non-periodic arrangement of Ag atoms within the precipitate. In the equilibrium stage, the incorporated Ag atoms in the precipitates release into the alpha-Al matrix as solute atoms or form Ag particles. In general, Ag atoms undergo a process of “segregate at the precipitate/matrix interface -> incorporate into the interior of precipitate -> release into the alpha-Al matrix” during the precipitation for Al-Mg-Si-Ag alloys. Besides, Ag segregation is found at the interfaces of almost all metastable phases (including GP zone, beta '', beta'/beta'(Ag) phase) in Al-Mg-Si-Ag alloys. The Ag segregation at the beta'/alpha-Al interface could increase the length/diameter ratio of beta' phase and thus promote the additional strengthening potential of these alloys. These findings provide a new route for precipitation hardening by promoting the nucleation and morphology evolution of precipitates. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000495519100028 Publication Date 2019-09-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.301 Times cited Open Access (down)
Notes Approved Most recent IF: 5.301
Call Number UA @ admin @ c:irua:164641 Serial 6295
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