Showing papers in "Acta Materialia in 2012"

TL;DR: In this paper, the Inconel 718 cylinders were fabricated by selective laser melting in either argon or nitrogen gas from a pre-alloyed powder, and they exhibited columnar grains and arrays of oblate ellipsoidal precipitates oriented in a strong [2.0.0] texture determined by combined optical metallography, transmission electron microscopy, and X-ray diffraction analysis.

TL;DR: In this article, a comprehensive study of the densification behavior, phase and microstructure development, hardness and wear performance of commercially pure Ti parts processed by selective laser melting (SLM) is presented.

TL;DR: In this article, an Al 0.5 CoCrCuFeNi high entropy alloy (HEA) was used to study the fatigue behavior of the Alloy and a Weibull mixture predictive model was applied to predict the fatigue data and characterize the variability seen in the HEAs.

TL;DR: In this article, the intrinsic stacking fault I1 energy (I1 SFE) was investigated by transmission electron microscopy and density functional theory, and the influence of the SFE on the relative activation of different competing deformation mechanisms (basal, prismatic, pyramidal slip) was discussed.

TL;DR: In this article, the authors investigated the kinetics of the deformation structure evolution and its contribution to the strain hardening of a Fe 30.5Mn-2.1Al-1.2C (wt.%) steel during tensile deformation by means of transmission electron microscopy and electron channeling contrast imaging combined with electron backscatter diffraction.

TL;DR: In this paper, structural models of the unique long period stacking/order (LPSO) phases formed in Mg-Zn-RE alloys, based on Z-contrast scanning transmission electron microscopy observations and first principles calculations, were proposed.

TL;DR: In this paper, a bulk nanostructured 316L austenitic stainless steel consisting of nano-sized grains embedded with bundles of nanometer-thick deformation twins was synthesized.

TL;DR: In this article, the effect of grain size on hydrogen diffusion and trapping mechanisms was investigated for a wide range of grain sizes of non-textured pure nickel, and the effects of grain boundaries on different defects and trapping sites stored in the GBs, and their consequences on hydrogen transport and segregation.

TL;DR: In this paper, the compositions of grain boundaries (GBs) and other interfaces surrounding Nd 2 Fe 14 B sintered magnets have been investigated by laser-assisted three-dimensional atom probe to understand the mechanism of the coercivity enhancement by post-sinter annealing.

TL;DR: In this article, the lattice parameters, formation energies and bulk moduli of (Ti, M)C and M(C, Va) with the B1 crystal structure have been investigated using first-principles calculations, where M = Nb, V, Mo and W.

TL;DR: In this article, the effects of Al on microstructure, stacking fault energy, tensile properties and fractured surface in Fe-18Mn-06C-(0-2)Al twinning-induced plasticity (TWIP) steels were systemically investigated.

TL;DR: In this article, the strontium distribution was studied in atomic resolution by atom probe tomography and in nanometre resolution by transmission electron microscopy, and the combined investigations indicated that Sr co-segregates with Al and Si within the eutectic Si phase.

TL;DR: In this paper, the authors investigated the dependence of the width of void-denuded zones (VDZs) on grain boundary (GB) characters in Cu irradiated with He ions at elevated temperature.

TL;DR: In this article, the microstructure associated with the hydrogen-induced features on the fracture surface of a lath martensitic steel has been visualized in a transmission electron microscope by using focused-ion beam machining to extract samples perpendicular to the fracture surfaces.

TL;DR: Using a combination of high-resolution scanning and transmission electron microscopy, the basic mechanisms of hydrogen-induced intergranular fracture in nickel have been revisited in this paper using focused-ion beam machining.

TL;DR: In this article, the authors used finite element modeling with an analytical component to evaluate the thermal characteristics in quasi-constrained high pressure torsion (HPT) processing.

TL;DR: In this paper, a microstructural analysis of the twins in deformed samples was presented to explain the yield elongation and in particular why it decreases and eventually disappears with increasing grain size.

TL;DR: In this article, fracture surface features were studied and compared using high-resolution surface-sensitive scanning electron microscopy, and the deformation microstructures just beneath the fracture surfaces were studied using transmission electron microscope, providing a mechanistic view of failure catalyzed by hydrogen.

TL;DR: In this paper, a series of dense BaTiO3 ceramics with uniform grain-size distribution were successfully prepared by the conventional solid-state reaction, and the grainsize effects on the dielectric and piezoelectric properties were explored in their poled states.

TL;DR: In this article, the formation of ω-like embryos from competing compositional and structural instabilities arising in the bcc lattice of binary titanium-molybdenum alloys during rapid cooling from the high-temperature single β phase field was investigated.

TL;DR: In this paper, the Gibbs-Ashby model was used to evaluate the compression fatigue behavior of Ti-6Al-4V mesh arrays with high porosities of ∼60-85%, which were fabricated by additive manufacturing technique using electron beam melting.

TL;DR: In this article, the effects of transformation temperature on the variant pairing tendency of bainitic ferrite and the orientation relationship between BF and austenite matrix are investigated quantitatively in low-carbon, low-alloy steel by means of electron backscatter diffraction analysis.

TL;DR: In this article, the elasticity-driven morphology of the nanosized particles after coarsening at 1573 K was determined based on transmission electron microscopy, which revealed the coherent misfitting character of the parent phases.

TL;DR: In this article, the anisotropic elastic and thermal properties of layered compounds in the series Ln 2 SrAl 2 O 7 (Ln = La, Nd, Sm, Eu, Gd or Dy) are calculated from first principles using density functional theory combined with the Debye quasi-harmonic approximation.

TL;DR: In this article, the diffusional displacive 18R to 14H transformation rate is controlled by the diffusion rate of Y and Zn atoms into the segregation layers in a Mg-8Y-2Zn-0.6Zr alloy.

TL;DR: In this paper, the effects of the hot rolling degree of deformation on the mechanical properties of the composites are investigated by experiment and modeling, in particular, the variation in the inclination of the TiB whiskers during rolling is quantified in the model.

TL;DR: In this paper, the authors investigated the effect of ZrO2-based thermal barrier coating (TBC) ceramics on their interactions with molten Ca-Mg-Al-silicate (CMAS) glass.

TL;DR: In this article, the microstructural evolution of a polycrystalline Ni-based superalloy (Alloy 617B) for power plant applications at a service temperature of 700°C was reported.

TL;DR: In this article, a combination of accumulative roll bonding (ARB) and rolling is used to fabricate nanolamellar Cu-Nb multilayers with individual layer thicknesses (h) of 600μm − 10nm with a total strain imposed between 0.5 and 11.6.

TL;DR: A comprehensive overview of multiferroic and magnetoelectric materials can be found in this article, including details on the nature of order parameters and coupling in these materials, the scarcity of such materials in single phase form, routes to create and control the properties of these materials and the effects of such effects in a number of model materials and heterostructures.