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Showing papers in "Acta Materialia in 2007"


Journal ArticleDOI
TL;DR: In this paper, a review of recent advances in understanding the mechanical behavior of metallic glasses, with particular emphasis on the deformation and fracture mechanisms, is presented, where the role of glass structure on mechanical properties, and conversely, the effect of deformation upon glass structure, are also described.

2,858 citations


Journal ArticleDOI
TL;DR: A brief overview of the recent progress made in improving mechanical properties of nanocrystalline materials, and in quantitatively and mechanistically understanding the underlying mechanisms is presented in this paper.

994 citations


Journal ArticleDOI
TL;DR: In this article, the rolling textures of six magnesium alloys containing different levels of zinc and rare earth (RE, e.g. mischmetal or Y) additions are examined. And the influence of texture on the mechanical response is investigated.

947 citations


Journal ArticleDOI
TL;DR: In this article, the authors show how carbon affects martensitic transformations in Ni-rich NiTi shape memory alloys and provide new experimental evidence for increasing temperature intervals between the start and the end of the martenitic transformations (from B2 to B19′) with increasing C content in as-cast and solution-annealed microstructures.

706 citations


Journal ArticleDOI
TL;DR: In this paper, the formation of regular patterns is a common feature of many solidification processes involving cast materials, and regular patterns can be obtained in porous alumina by controlling the freezing of ceramic slurries followed by subsequent ice sublimation and sintering.

683 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of external stress and stacking fault energies (SFE) on the width of the stacking faults were analyzed and an excellent correlation between the calculations and actual microstructures examined by scanning electron microscopy was found.

678 citations


Journal ArticleDOI
TL;DR: In this article, three-dimensional viscoplastic flow and heat transfer during friction stir welding of mild steel was investigated both experimentally and theoretically, and the equations of conservation of mass, momentum and energy were solved in three dimensions using spatially variable thermo-physical properties and a methodology adapted from well established previous work in fusion welding.

556 citations


Journal ArticleDOI
TL;DR: In this paper, the existence of multiple interface complexions in a real-world material system has been proven by thermodynamics, and it has been shown that an interface complexion can be considered as a separate phase which can be made to transform into different phases with vastly different properties by chemistry and heat treatment.

524 citations


Journal ArticleDOI
TL;DR: In this article, the effect of compressive pre-deformation on subsequent tensile deformation behavior in a hot-extruded AZ31 Mg alloy bar with a ring fiber texture, and with the basal planes parallel to the extrusion direction was examined.

518 citations


Journal ArticleDOI
TL;DR: In this article, the authors reported an explanation for the inverse Hall-Petch effect based on the statistical absorption of dislocations by grain boundaries, showing that the yield strength is dependent on strain rate and temperature and deviates from the Hall-petch relationship below a critical grain size.

459 citations


Journal ArticleDOI
TL;DR: In this paper, the evolution of twinning and texture in two Mg-based (+Al, Mn, Zn) alloys was investigated using uniaxial tension, unioxial compression and ring hoop tension testing at temperatures from ambient to 250°C and a strain rate of 0.1 s−1.

Journal ArticleDOI
TL;DR: In this paper, the microstructures of age hardened Mg-2.0Gd-1.2Y-xZn-0.2Zr (x = 0, 0.3, and 1.0) (at.%) alloys were investigated to understand the remarkable age-hardening and unusual plastic elongation behavior.

Journal ArticleDOI
TL;DR: Indentation is a remarkably flexible mechanical test due to its relative experimental simplicity as discussed by the authors, and the ease of implementation has made indentation a ubiquitous research tool for a number of different systems across size scales (nano to macro) and scientific/engineering disciplines.

Journal ArticleDOI
TL;DR: In this article, a time-temperature-transformation diagram of an Mg-Zn-Gd alloy is proposed, which shows different precipitation sequences at low, medium and high temperatures.

Journal ArticleDOI
TL;DR: In this article, a solution-treatment to partially dissolve T-phase particles, cryo-rolling to produce a fine-structure containing a high density of dislocations and submicrometer subgrains and aging to generate highly dispersed nano-precipitates.

Journal ArticleDOI
TL;DR: In this article, the Gibbs adsorption isotherm and Wagner's definition of excess solute at surfaces and grain boundaries are both extended to include other crystalline defects, like dislocations and vacancies.

Journal ArticleDOI
TL;DR: In this article, the evolution of microstructure and the mechanical response of copper subjected to severe plastic deformation using equal channel angular pressing (ECAP) was investigated, and it was shown that the microstructures produced through adiabatic shear localization during high strain rate deformation and ECAP are very similar.

Journal ArticleDOI
TL;DR: In this paper, composite of Mg reinforced with 0.5, 1 and 2 vol.% of Y2O3 nanoparticles were fabricated using disintegrated melt deposition technique.

Journal ArticleDOI
TL;DR: In this article, a hierarchical theory was proposed to predict critical twinning stress in face-centered cubic metals without any empiricism at any length scale, and the theory predicts a monotonic relation between the unstable twin stacking fault energy and twin nucleation stress revealing the physics of twinning.

Journal ArticleDOI
TL;DR: It is reasoned through experimental evidence that greater understanding of the mechanics of cancer cell deformability and its interactions with the extracellular physical, chemical and biological environments offers enormous potential for significant new developments in disease diagnostics, prophylactics, therapeutics and drug efficacy assays.

Journal ArticleDOI
TL;DR: In this paper, microstructural properties of hot isostatically pressed Ti-6Al-4V alloy with 0, 0.05, 0., 10, and 0.40 wt.% B additions have been examined, with particular emphasis on identifying the micro-structural length scale (grain size vs. lath size) that controls the mechanical properties of these alloys.

Journal ArticleDOI
TL;DR: In this article, the micro-hardness of high-purity aluminum was measured along diameters in each disk and following a rectilinear grid pattern to give color-coded maps of the hardness distributions.

Journal ArticleDOI
TL;DR: A detailed analysis of the reaction mechanism of the reactive hydride composite (RHC) was performed using high-pressure differential scanning calorimetry (HP-DSC) measurements and in situ synchrotron powder X-ray diffraction (XRD) measurements along with kinetic investigations using a Sievert-type apparatus as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, the strain-induced grain refinement process in AZ91D alloy includes three steps, at the initial stage twinning dominates the plastic deformation and divides the coarse grains into finer twin platelets, with increasing strain, double twins and stacking faults form and a number of dislocation slip systems are activated.

Journal ArticleDOI
TL;DR: In this paper, a large database of solute-vacancy binding energies determined from first-principles density functional calculations was reported, and the calculated binding energies agree well with accurate measurements where available, and provide an accurate predictor of solutes binding in other systems.

Journal ArticleDOI
TL;DR: In this paper, a fine-scale bainitic microstructure with high strength and high toughness has been achieved by transforming austenite at 200°C. X-ray diffraction analysis showed the carbon concentration of these bainite ferrite plates to be higher than expected from para-equilibrium.

Journal ArticleDOI
TL;DR: In this article, the extended version of the Gibbs adsorption isotherm including dislocations and vacancies is used to analyse existing experimental data, and the analysis of experimental results addresses the question whether zero or negative defect energies are feasible and how this will affect materials behaviour.

Journal ArticleDOI
TL;DR: In this paper, the authors introduce a model for twinning, which accounts explicitly for the composite character of the grain, formed by a matrix with embedded twin lamellae which evolve with deformation.

Journal ArticleDOI
TL;DR: In this paper, the mechanical behavior of transformation-induced plasticity (TRIP)-assisted multiphase steels is addressed based on three different microstructures generated from the same steel grade.

Journal ArticleDOI
TL;DR: In this paper, the relationship between yield strength, relative density and ligament sizes is presented for nanoporous Au foams, and the ligament length scale is used as a new parameter to tailor foam properties and achieve high strength at low densities.