Showing papers in "Acta Materialia in 2017"

TL;DR: High entropy alloys (HEAs) are barely 12 years old as discussed by the authors, and the field has stimulated new ideas and inspired the exploration of the vast composition space offered by multi-principal element alloys.

TL;DR: The tensile properties of CrCoNi have been shown to be significantly better than those of CrMnFeCoNi, a high-entropy alloy as discussed by the authors, and the deformation mechanism responsible for its superiority has been investigated.

TL;DR: In this paper, the deformation behavior and microstructure evolution of the eutectic and near-eUTectic high entropy alloys were thoroughly studied using a combination of techniques, including strain measurement by digital image correlation, in-situ synchrotron X-ray diffraction, and transmission electron microscopy.

TL;DR: In this article, an in-situ nano-TiB 2 decorated AlSi10Mg composite (NTD-Al) powder was fabricated by gas-atomisation for selective laser melting (SLM).

TL;DR: In this paper, a high-strength CoCrNi-based medium-entropy alloy hardened by nanoscale L1 2 -(Ni, Co, Cr) 3 (Ti, Al)-type particles with mixing heterogeneous and homogeneous precipitation behaviors was reported.

TL;DR: In this article, the authors present a systematic microstructure oriented mechanical property investigation for a newly developed class of transformation-induced plasticity-assisted dual-phase high-entropy alloys (TRIP-DP-HEAs) with varying grain sizes and phase fractions.

TL;DR: In this paper, an AlCoCrFeNi2.1 eutectic high-entropy alloy was prepared with face-centered cubic (FCC)(L12)/body-centered-cubic (BCC)(B2) modulated lamellar structures and a remarkable combination of ultimate tensile strength (1351 MPa) and ductility (15.4%) using the classical casting technique.

TL;DR: In this article, the lattice parameter of the β phase in the (α+β) lamellae falls into a specific range of 3.18-3.21 A. The lattice parameters can serve as an indicator to predict whether significant martensite decomposition has taken place in situ in Ti-6Al-4V made by SLM.

TL;DR: In this paper, high-entropy alloys (HEAs) are multi-component systems based on novel alloy composition designs with entropy maximization They feature an array of unique mechanical properties when compared with traditional alloys.

TL;DR: In this paper, the authors investigated the origin of the exceptional properties of NiCoCr alloy, which are related to the evolution of the deformation substructure with strain, interrupted tensile testing was conducted on the equiatomic NiCo-Cr single-phase solid solution alloy at both cryogenic and room temperatures at five different plastic strain levels of 1.5, 6.5%, 29, 50% and 70%.

TL;DR: In this paper, the effect of the aspect ratio of carbon nanotubes (CNTs) on aluminum metal matrix composites (Al MMCs) was studied and the tensile results showed that the CNTs exhibited a strong strengthening effect in the composites regardless of their aspect ratios.

TL;DR: In this article, the stacking fault energy (SFE) for a series of face-centered cubic (fcc ) equiatomic concentrated solid solution alloys (CSAs) derived as subsystems from the NiCoFeCrMn and NiCo FeCrPd high entropy alloys based on ab initio calculations was reported.

TL;DR: Numerical simulations are used in this work to investigate aspects of microstructure and microseg-regation during rapid solidification of a Ni-based superalloy in a laser powder bed fusion additive manufacturing process.

TL;DR: In this paper, a new theory has been developed that builds on one historical model, the Labusch model, in important ways that lead to a well-defined model valid for random solutions with arbitrary numbers of components and compositions.

TL;DR: In this article, different processing parameters, including four different hatch styles, as well as contour and base plate heating, were employed to evaluate their impact on the room temperature tensile properties.

TL;DR: In this article, the microstructure, composition, phases, and microhardness were determined as a function of position within a functionally graded materials (FGMs), and detrimental phases associated with the compositional blending of the Ti-6Al-4V and Invar formed, leading to cracking in the final part.

TL;DR: In this article, the formation of secondary phases at high temperatures, and their effect on mechanical properties, is investigated using the AlxCoCrFeNi (x = 0.3, 0.5, and 0.7) as a model alloy.

TL;DR: In this article, the microstructural response and grain subdivision process in commercially pure (CP) titanium subjected to multiple laser shock peening (LSP) impacts were investigated by means of optical microscopy (OM), scanning electron microscopy and transmission electron microscope (TEM) observations.

TL;DR: In this article, a digital twin of the laser-based directed energy deposition additive manufacturing (DED) process is proposed to provide accurate predictions of the spatial and temporal variations of metallurgical parameters that affect the structure and properties of components.

TL;DR: In this article, a high-fidelity powder-scale model is developed to predict the detailed formation processes of single/multiple-track defects, including the balling effect, single track nonuniformity and inter-track voids.

TL;DR: In this article, the authors investigated the influence of porosity variation in electron beam melting (EBM)-produced β-type Ti2448 alloy samples on the mechanical properties including super-elastic property, Young's modulus, compressive strength and fatigue properties.

TL;DR: In this paper, a new class of high-entropy alloys (HEAs), quinary (five-component) dual-phase (DP) HEAs revealing transformation-induced plasticity (TRIP), designed by using a quantum mechanically based and experimentally validated approach.

TL;DR: In this article, the authors explored the mechanical properties of high entropy alloys and complex concentrated alloys (CCAs) by comparing them with commercially available engineering alloys including industry-standard aerospace alloys.

TL;DR: In this article, an aluminum carbide (Al4C3) nanostructure at the end of the MWCNTs, incorporated in the Al matrix, was produced by appropriate heat-treatment.

TL;DR: In this paper, the authors review the new and unexpected results obtained on dislocation cores from first principles, including the identification of unforeseen stable and metastable cores and the quantitative evaluation of both interaction energies and energy pathways, in pure metals and alloys of different crystallography (FCC, BCC, HCP) as well as semiconductors.

TL;DR: In this article, the authors would like to thank the EPSRC/Rolls-Royce Strategic Partnership for funding (EP/M005607/1 and EP/H022309).

TL;DR: In this article, the authors used analytical scanning and transmission electron microscopy to characterise Selectively Laser Melted (SLM) CM247LC powder and found that longitudinal sections consist mainly of columnar γ grains, containing virtually identically oriented cells, approximately 700nm in width and length up to hundreds of microns.

TL;DR: In this paper, the influence of different (0002) distributions on k for twinning and slip was systematically studied using an AZ31 rolled plate ([0002]//ND) and extruded rod (0002]⊥ED together with a random distribution around the ED).

TL;DR: In this article, the Intrinsic Heat Treatment (IHT) was exploited to induce the precipitation of NiAl nanoparticles in an Fe-19Ni-xAl (at%) model maraging steel, a system known for rapid clustering.

TL;DR: In this paper, the authors report a giant strain (0.72%) with a low degree of hysteresis (ca. 36.2%) and a giant Smax/Emax ratio (916 pm V−1, Smax and Emax denote the maximum strain and the corresponding electric field, respectively) for lead-free (1−x) 0.95 piezoceramics with x = 0.06.