Showing papers in "Acta Materialia in 2015"

TL;DR: In this article, the authors investigated the anisotropic mechanical properties of a Ti-6Al-4V three-dimensional cruciform component fabricated using a directed energy deposition additive manufacturing (AM) process.

TL;DR: In this article, an equiatomic CoCrFeMnNi high-entropy alloy (HEA), produced by arc melting and drop casting, was subjected to severe plastic deformation (SPD) using high pressure torsion.

TL;DR: In this paper, a new ultrafine lamellar microstructures comprising ultrafine (∼200-300nm) α-laths and retained β phases were created via promoting in situ decomposition of a near α′ martensitic structure in Ti-6Al-4V additively manufactured by selective laser melting (SLM).

TL;DR: In this paper, the development of surface structure and porosity of Ti-6Al-4V samples fabricated by selective laser melting under different laser scanning speeds and powder layer thicknesses has been studied and correlated with the melt flow behavior through both experimental and modelling approaches.

TL;DR: In this article, a liquid metallurgy synthesized, non-equiatomic Fe 40 Mn 40 Co 10 Cr 10 high entropy alloy is designed to undergo mechanically-induced twinning upon deformation at room temperature.

TL;DR: In this paper, the microstructure and mechanical properties of EBM-built Ti-6Al-4V have been systematically investigated in the presence of columnar prior β grains delineated by wavy grain boundary α and transformed α/β structures.

TL;DR: In this article, an as-fabricated Al-12Si alloy with controllable ultrafine microstructure and excellent mechanical properties can be achieved by using selective laser melting and subsequent solution heat treatment.

TL;DR: In this paper, the authors investigated the effect of the fundamental solid solution strengthening (SSS) effect on the tensile strength of Hastelloy X, a common nickel-base superalloy of known high crack susceptibility when processing SLM.

TL;DR: In this article, the authors discuss some of the challenges that must be overcome to enable widespread use of thermoelectric power generation (TEG) devices, including thermal stability at the material level, and reliable contact at the device level.

TL;DR: In this article, the authors used Mooren's approach for the computation of interatomic spacing in multicomponent alloys, allowing the creation of a model for elastic misfit in high entropy alloys.

TL;DR: In this paper, a high-resolution electron microscopy investigation has confirmed the existence of a Ti-rich monolayer on the surface of the (0.0, 0.1) TiB2 surface, which is most likely to be a (1 − 1 2 ) Al3Ti 2DC.

TL;DR: In this article, an index for the susceptibility of an alloy to cracking during solidification was also proposed, that is, |dT/d(fS1/2)| near (fS) 1/2 ǫ = 1, where T is temperature and fS the fraction solid in the semisolid.

TL;DR: In this paper, the authors investigated the thermodynamic properties of the prototype equi-atomic high entropy alloy (HEA) CoCrFeMnNi by using finite-temperature ab initio methods.

TL;DR: In this article, a gradient nanostructured (GNS) surface layer was formed on AISI 316L stainless steel and the mean grain size is ∼30nm in the topmost surface layer and increases with depth.

TL;DR: In this paper, the authors investigated the influence of stacking-fault energy (SFE) on the microstructural and strain-hardening evolution of three TRIP/TWIP alloys.

TL;DR: In this paper, the fatigue behavior of a cold-rolled two-phase Al0.5CoCrCuFeNi high-entropy alloy (HEA) was studied.

TL;DR: In this paper, the impact of grain size and manganese concentration on the austenite stability and deformation behavior of a cold-rolled transformation-induced plasticity (TRIP) steel with a nominal chemical composition of Fe-11Mn-4Al-02C (wt%) was elucidated.

TL;DR: In this paper, the concentration dependence of the martensite start temperature (M S ) in Ni-Ti-based shape memory alloys (SMAs) was investigated and it was shown that the strong dependence of M S on alloy composition in binary, ternary and quaternary SMAs is due to a stabilization of the B2 phase by structural relaxations around Ni antisite atoms.

TL;DR: In this article, trace boron addition to Ti-6Al-4V coupons produced by additive layer manufacturing is an effective way to eliminate the deleterious anisotropic microstructures often encountered with this manufacturing technique.

TL;DR: In this paper, the authors systematically investigated the stress-strain behavior of ferrite and bainite with nano-sized vanadium carbides in low carbon steels, and the results showed that nano-size carbides may act as sites for dislocation multiplication in the early stage of deformation, while they may enhance dislocation annihilation in the later stage.

TL;DR: In this paper, the evolution of the structure and microstructure of the equimolar CrMnFeCoNi high entropy alloy was investigated during processing under varying conditions (cooling rate and annealing duration).

TL;DR: In this article, a well-controlled micro cantilever bending experiment on a copper bicrystal has been analyzed by 3D electron back scatter diffraction (3D EBSD).

TL;DR: In this article, the authors studied grain boundary embrittlement in a quenched and tempered Fe-Mn high-purity model martensite alloy using Charpy impact tests and grain boundary characterization by atom probe tomography.

TL;DR: In this article, a new model describing the microstructure and strength of lath martensite is introduced, where the lattice distortion energy within a lath being equal to the strain energy of the dislocation density at the lath boundaries.

TL;DR: In this article, a new model for the yield stress in superalloys accounting for unimodal and multimodal size distributions is presented and important features not previously considered are incorporated in the model.

TL;DR: In this article, the authors investigated the temperature and rate dependence of slip, twinning, and secondary twinning in high-purity hexagonal close packed α-Zr over a wide range of temperatures and strain rates.

TL;DR: In this paper, the influence of grain size on the twinning stress of an Fe-15Mn-2Al-2Si-0.7C twinning induced plasticity (TWIP) steel was investigated.

TL;DR: In this paper, a model has been developed to forecast the thermal runaway conditions and the predictions are in excellent agreement with the observed onset flash temperatures, attesting that the flash starts as a thermal runaway in at least these ZnO based systems.

TL;DR: Achieving high strength and uniform deformation simultaneously in Al alloys processed by severe plastic deformation (SPD) remains a challenging task as these alloys usually possess high strength but very limited uniform deformability.

TL;DR: In this paper, a Fe 9Mn−3Ni−1.4Al−0.01C (mass%) medium-Mn TRIP maraging steel is produced and heat-treated under different reversion conditions to introduce well-controlled variations in the austenite-martensite nanolaminate microstructure.