In the present study, a two-phase Ti2AlNb-based alloy with a nominal composition of Ti–22Al–25Nb (at%) comprising the dominant O + B2/β phase was explored. The microstructural evolution and tensile properties are studied by applying different heat treatment methods of water-cooling (WC, 140 °C/s) and furnace-cooling (FC, 0.08 °C/s) after heat treatment at 1015 °C for 40 min, followed by aging treatment

In the present work, interactions of nanoindentation-induced dislocations (NIDs) with a low-angle grain boundary (LAGB) are investigated in a single-crystalline CrCoNi medium-entropy alloy (MEA). Microstructural evolutions before and after nanoindentation were examined using accurate electron channeling contrast imaging. In the as-grown state, the alloy microstructure consists of subgrains separated

To overcome the brittleness of tungsten, tungsten fiber-reinforced tungsten composites (Wf/W) have been developed using an extrinsic toughening mechanism. In this work, a novel type of Wf/W with porous matrix produced by field assisted sintering technology (FAST) is studied. The material is optimized regarding mechanical behavior, standing on the adjusting of matrix porosity and fiber mass fraction

Interactions between slip bands (SBs) and interfaces in a compressed duplex stainless steel (DSS) are investigated regarding the roles of grain boundaries (GBs) and phase boundaries (PBs) in plastic deformation. Digital image correlation based on scanning electron microscopy, and electron backscatter diffraction are utilized to characterize SBs in ferrite and austenite phases, and the interactions

While Ti–Nb binary alloys have been extensively studied over the years, there are discrepancies in the literature relating to the β-α″ martensitic transformation that indicate an incomplete understanding. In particular, there are inconsistencies regarding the phase constitution of as-quenched material and the ability for α″ phase to be thermally-induced. To resolve these issues, the β-α″ phase transformation

Ti2AlNb (Ti–22Al–25Nb at.%, nominal composition) intermetallic is essential to aerospace industry from a weight reduction perspective, and brings a possibility of replacing some Ni-based superalloys. Despite evaporation of element Al (from its original composition 22.8 at.% to 18.5 at.%), selective laser melting (SLM) technology offers distinct advantages in fabricating Ti2AlNb intermetallic with superior

CoCrNi -medium-entropy alloy (MEA) has been widely investigated due to its superior mechanical properties that overcome strength-ductility tradeoff. Here we show further property enhancement of CoCrNi MEA by introducing nano-scale features. Both CoCrNi and oxide dispersion strengthened (ODS) CoCrNi are fabricated by mechanical alloying and spark plasma sintering. Microstructural characterization and

Laser metal deposition (LMD) shows outstanding advantages in manufacturing complex parts. In practice, some formed parts usually require directional properties in order to obtain better service performance in its use. This study has comprehensively analyzed the microstructure, texture and porosity of CrCoNi medium-entropy alloy thin-walled parts manufactured by LMD process, as well as the effect of

High-entropy alloys are a new class of multi-component alloys, which demonstrate outstanding strength-ductility combination, significant expanding the alloy design space in metallurgical research. However, the yield strength levels, are still low when compared with other high strength materials. Here, the non-equiatomic design concept was employed to improve the yield strength of the CoFeNi alloy through

Tensile tests of an ultrafine-grained metastable austenitic stainless steel (ASS) were carried out at 298, 253, and 173 K along with in situ high-energy X-ray diffraction (HE-XRD). We found that the interplane elastic compatibility of austenite and strain-induced α′-martensite (SIMα′) at 253 K was better than that at other temperatures. It was further detected that the martensitic transformation of

Inspections on microstructural design suggest that a high-strength Mg alloy can be achieved via the generation of co-precipitation of prismatic and basal precipitates with high number density and large aspect ratios. Currently, there is a lack of feasible approaches to generating such a microstructure. This work investigated the specific role of various Yb contents on the precipitation behavior, solute

Stretch-flangeability as a parameter of formability is measured on dual-phase (DP) and complex-phase (CP) steels by the hole-expansion ratio (HER), and nanoindentation is introduced to assess the hardness of constituent phases before and after HER testing. Hole-expansion ratios of two dual-phase (DP1, DP2) and one complex-phase (CP1) steels are measured as 51%, 126% and 136%, respectively. The primary

Considering the great potential of extremely-low temperature applications, cryogenic tensile properties and deformation behavior of a metastable β-Ti alloy Ti–15Mo–2Al were investigated. Superhigh ultimate tensile strength (UTS) of 1535 MPa at 77 K and 1725 MPa at 20 K are achieved. The elongation-to-fracture (EI) of the alloy is found to be maintained at a high level up to 22.0% at 77 K, but sharply

Imparting ductility to glass effectively counters brittleness caused by stress concentration. Spark plasma sintering of silica (SiO2) nanopowder and a silver nitrate mixture successfully dispersed silver (Ag) nanoparticles into a SiO2 glass matrix. The Ag-precipitated SiO2 glass showed crack bridging during crack propagation and softening owing to the ductility imparted by Ag. Compared with SiO2 glass

TNW700 is a newly developed near-α high temperature titanium alloy and has great application potential in the aerospace industry owing to excellent creep strength and short-term service temperature up to 700°C. The superplastic tensile deformation behavior and constitutive model of TNW700 alloy in the temperature range of 900-975°C and strain rate range of 0.0005-0.01s-1 were investigated. Results

In this work, a relationship between welding conditions, annealing behavior, and mechanical performance of friction-stir welded (FSWed) 6061-T6 aluminum alloy was examined. In the entire studied FSW range, the welded material was found to be unstable against abnormal grain growth during post-weld solutionizing treatment. However, a lowering of the FSW heat input tended to inhibit this undesirable phenomenon

In this work, the relationship between the accumulation and release of elastic energy during the flow serrations of a bulk metallic glass (BMG) was investigated by use of 10 groups of specimens under varying mixed-mode (I/II) loading conditions. The findings have shown that both the elastic energy accumulation rates and load drops have significant variations, and the load drop data are more scattered

Low ductility and toughness of molybdenum (Mo) alloys have usually been the bottleneck for their further application. Here, the improved strength together with ultra-high ductility and fracture toughness of Mo alloys were achieved by the incorporation of Mo2TiC2 (a typical MXene). Elongation of Mo-Mo2TiC2 alloys increased to 2.3-2.7 folds of pure Mo and the fracture toughness increased to 2.4 folds

The tungsten heavy alloy green parts are successfully manufactured by an innovative indirect 3D printing technology, powder extrusion printing. Then the subsequent debinding-sintering process of the printed green parts is optimized to obtain a high-density and suitable-contiguity alloy. Finally, a 96W-2.7Ni-1.3Fe alloy with a high density of ∼99.1%, suitable contiguity of ∼ 0.63, strength of ∼801MPa

Heterogeneous, partially recrystallized (PRX) microstructures have recently been used to improve strength-ductility combinations in high-entropy alloys. However, these microstructures are incompatible with conventional joining processes that require melting or prolonged exposure to elevated temperatures. This work presents an initial exploration of solid state joining in this challenging condition

Ni-free and Ni-bearing steels were designed to elucidate the effect of Ni on the free energy of bainitic transformation. Steels with two distinct nano-bainite structures were obtained through conventional one-stage and two-stage isothermal treatments. The effect of work hardening and accompanying strain on martensitic transformation of the two nano-bainite structures was also studied. Microstructure

Some reports on the mechanical testing of pure rhenium can be found in the literature. However, very few studies have been published regarding the fatigue properties of rhenium. To gain new knowledge on this subject, the present research aimed to determine mechanical properties in monotonic tension, hardness, and stress-controlled fatigue tests of sintered rhenium. The results of the basic mechanical

Effects of different V contents on microstructure and properties of Zr–Ti alloys are systematically investigated in this study. Microstructure of as-cast alloys is characterized by optical microscope, X-ray diffractometry, scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy. Mechanical properties of alloys are analyzed using compression and microhardness

In this study, a strong and ductile thin sheet of Mg–Zn–Zr alloy was developed through nano precipitates and pre-induced dislocation. Our results displayed that the sheet was comprised of fiber basal texture and a small fraction of the grains having c-axes//TD of the sheet. Most specifically, profuse pre-induced dislocations and nano-size precipitates were witnessed in the grain interior. During deformation

The ultrathin miniaturized metal foil has high sensitivity to strain rate due to the size effect during microforming processes. The correlations between the strain rate, size effect and microformability are still unclear at the micro-nano-scale. Hence, the coupling influence mechanism of strain rate and foil thickness on micro-deformation behavior of ultrathin (<20 μm) TA1 foil is investigated through

The CoCrFeNi HEAs offer immense promise for advanced engineering applications. However their strength at high temperatures needs much improvement. In an effort to strengthen the highly ductile matrix, here we report a CoCrFeNi composite in which a continuous network composed of TiN nanograins is placed around the FCC matrix. To accomplish this, initially a CoCrFeNi powder with an in-situ coating of

In this study, the effects of microstructure, temperature and dwell time in a loading cycle on low cycle fatigue (LCF) and stress relaxation behaviours of a powder metallurgy Ni-based superalloy (i.e. FGH4098) for aeroengine turbine disc application were studied along with detailed microscopic characterisation of fracture features and deformation substructures. The results indicate that the LCF failure

The effects of solid solution treatment on microstructure and mechanical properties of SiCp/2024 Al matrix composite fabricated via powder thixoforming were investigated, as well as those of 2024 matrix alloy for comparison. The results indicate that the solution progress of the composite is more hysteretic than that of the alloy due to the obstacle role of SiCp to eutectic dissolution and grain coarsening

The unique thermal history of different metal additive manufacturing processes would have profound impacts on the resulting microstructure and material properties. However, few have conducted benchmark research on the impacts. This work provides a comprehensive benchmark comparison on microstructure, mechanical properties, and their underlying mechanisms in selective laser melting (SLM), electron beam

The Ni-based Hastelloy X (HX) superalloy is widely used in aero-engine components because of its exceptional high-temperature strength and oxidation resistance. Given the complex structure of such parts, additive manufacturing (AM) technologies such as laser powder bed fusion (LPBF) are employed to manufacture these components. HX alloy suffers from crack susceptibility during the LPBF process, however

The medium W content W–Ni–Fe alloys have a combination of high strength and great ductility, revealing a promising future for widespread engineering applications. In order to fabricate medium W content W–Ni–Fe alloys with outstanding performances, W nano-powders prepared by a two-stage reduction method was employed as raw material. Meanwhile, the finely dispersed Al2O3 particles have effective roles

The composite structures of TZM alloy and 30CrMnSiA steel have broad application prospects in nuclear power and aerospace industries, while the problem of the joint embrittlement has not been solved. Therefore, pure vanadium, which has excellent metallurgical compatibility with base materials is selected as the filler metal to produce high strength joints. Microstructures, mechanical properties, and

The effect of Y concentration on the slip and twinning mechanisms in binary Mg-Y alloys are investigated using transmission electron microscopy, electron backscattered diffraction, and visco-plastic self-consistent polycrystal constitutive modeling. Four concentrations of Y are studied in hot-rolled and recrystallized sheet material. The materials were deformed in tension and compression in the rolling

The present work has been devoted to study of β-solidifying γ-TiAl alloys based on Ti-44Al-0.2B and doped with Nb, Zr and Zr + Hf. The phase transformation sequences were established for the alloys. On this basis, upset forging followed by heat treatment was performed that resulted in formation of near the same duplex type microstructures in the alloys. Tensile tests in the temperature range of 20-900°C

Many alloys produced by Laser Powder Bed Fusion (LPBF) suffer from coarse grains and anisotropic mechanical properties. Here, we investigate how the addition of Ti can cause significant strengthening via grain refinement in a model ferritic stainless steel. We perform LPBF experiments using elemental Fe, Cr, and Ti powders (with significant O impurity in the Fe powder) and perform microstructural analysis

This paper discusses how the accumulative alternating back extrusion (AABE) process was improved by the addition of water-quench and preheating steps to mitigate the of temperature-drop problem caused by long process flows and the problem of die gap feeding. The effect of the number of extrusion cycles on grain refinement was further investigated to elucidate and rationalize the preferred orientation

The aim of this study was to identify deformation behavior and strengthening mechanisms of a carbon nanotube (CNT)-reinforced bimodal-grained Al-Cu-Mg nanocomposite and its base alloy fabricated by two-step ball milling, powder metallurgy and extrusion. A superior strength-ductility synergy stemming from the concurrent presence of ultrafine grains (UFGs) and coarse grains (CGs) was achieved. Singly-dispersed

High-strength and high-modulus Mg-10Gd-3Y-1Zn-0.4Zr (GWZ1031K, wt.%) alloy matrix composite reinforced with aluminum borate whiskers (Al18B4O33w) was fabricated by squeeze casting. The microstructure, interfacial characteristics, mechanical properties and fracture behavior of the composite were investigated. The results indicate that the grains of Mg matrix were significantly refined from 19±2μm to

Hydrogen embrittlement is a phenomenon that causes the deterioration of mechanical properties of steel, such as ductility, owing to hydrogen present inside the material and is a crucial factor that determines the reliability of structural materials. Hydrogen embrittlement is controlled by two kinetics—trapping and diffusion of hydrogen present in the material—and these are affected by microstructural

In the last decades, biomaterials have improved the life and its quality for millions around the Globe. Titanium-based biomaterials have rapidly become the gold standard for bone contact applications. Despite their successful performance, their low strength-ductility trade-offs and work-hardening rates limit their use for example for the manufacture of vascular stents. Although a high strength-ductility

EP741NP superalloy was fabricated by laser powder bed fusion (LPBF) and subsequently subjected to different heat treatments including hot isostatic pressure (HIP), solution + aging, HIP + solution + aging. The structural features of the alloy in the as-built condition as well as after heat treatment were studied and compared to its mechanical characteristics such as hardness, tensile strength, impact

Most complex engineering components experience varied loading in use. We conducted successive experiments of cyclic tensile deformation followed by electron-backscattered diffraction imaging of the same area on each of several magnesium alloy (ZM) sample to investigate the microstructure and texture evolution during cyclic loading. In this way we correlated the evolving deformed microstructure of cyclically

The effects of cold drawing process on the microstructure, mechanical properties and electrical conductivity of low-oxygen copper wires were studied. The results show that at low drawing strains (ε ≤ 1.23), the plastic deformation is dominated by planar slip, some of grains are rotated along the drawing direction, giving rise to a <111> texture. At medium strains (1.23 < ε ≤ 1.91), most of grains have

This article unmasks the probabilistic nature of high-pressure die casting; specifically, the cause of scatter in the tensile ductility of die-cast Al8Si0.4Mn0.3Mg (wt.%) alloy. Scatter in tensile ductility is related to the size of large pores and non-metallic inclusions. We propose that these non-metallic inclusions form during the pyrolysis of commercial plunger lubricants, and that these large

This work focused on ultra-high strength steel strengthened by Cu-rich multistructured precipitates and toughened by bainite. A Cr-Mo bearing bainitic steel was designed and contrasted with a ferritic steel to examine the effects of Cr and Mo on microstructural transformation and precipitation evolution as well as the corresponding mechanical properties. By adding Cr and Mo elements, bainitic steel

Two-cycle accumulative roll bonding (ARB) process was applied to produce sandwiched 2N-Al (99.2% purity) sheets (referred as ARB6/ARB2/ARB6) initially containing 2-cycle ARB processed core-layers (shorted as ARB2 layer) with coarse grains and 6-cycle ARB processed outer-layers (shorted as ARB6 layer) with fine grains. The ARB6/ARB2/ARB6 (shorted as ARB6/2/6) sheets were further annealed at various

Strain rate sensitivity and deformation mechanisms of closed-cell aluminium foams under low-velocity impact loadings are investigated in this study. Instrumented drop-weight impact experiments and Finite Element (FE) modelling were conducted to explore the deformation rate dependency of aluminium foams (manufactured by CYMATTM corporation). An X-ray micro-Computed Tomography (XCT) reconstructed foam

Addition of Mo to the face-centered cubic (fcc) NiCoCrFe base alloy is an attractive method for improving the solid-solution strengthening of high-entropy alloys (HEAs). However, the low solubility of Mo in the equiatomic base alloy limits implementation. In this study, we used thermodynamic and ab initio calculations to develop an off-equiatomic NiCoCrFe-based HEA with an Mo content of up to 11.11

Low alloy ferritic steels are widely used to manufacture critical components that operating at elevated temperatures in the process industry, but a better understanding of the creep responses of their weldments are still needed to provide guidance for the design of high-temperature welded structures. In the present paper, the heterogeneous creep behavior of vanadium-modified 2.25Cr1Mo ferritic steel

The manufacturing of titanium alloy components is of great significance for many industrial applications. High-performance titanium alloy parts are generally produced by a serial operation of hot forging process and extensive machining. Recently, additive manufacturing (AM) technologies such as direct laser deposition (DLD) has been developed to produce net-shape components. In this study, the parts

Two novel alloys of AZE311 and AZX311 were designed through adding 1 wt% Gd and Ca to the AZ31 alloy, respectively. To study the hot deformation behavior, compression tests were conducted at temperatures of 200–350 °C and the strain rates of 0.001–0.1/s. The conventional strain-related Arrhenius-type constitutive equations were developed based on the true stress-strain curves. The activation energy

The principle of “stress equivalence” proposed by Basinski et al. offers insight regarding the nature of thermally activated plasticity of solid solution alloys of FCC and HCP (Mg) crystal structures at low temperatures. More recently, Leyson and Curtin have developed a theoretical framework which builds upon the Labusch solute strengthening model. The current work analyzes some recent results from

The effect of the Ni/Cu-rich aluminides on the strength of Al-15%Mg2Si-Cu-Ni alloys at room and elevated temperatures was analyzed and revealed. The contribution of aluminides to alloys’ strength is promoted with the temperature increasing from 25 °C to 350 °C. Both Mg2Si and aluminides strengthen Al matrix and carry the load at room temperature (25°C). The thermal stable and interconnected aluminides

In this study, the effect of post-deposition heat treatments on an Al-Mg-Si alloy processed with additive friction stir deposition (AFS-D), a solid-state additive manufacturing process, is examined. Results reveal that wrought-like microstructure and mechanical properties are achievable in AFS-D builds through the application of a post-deposition heat treatment.

Metastable β-Ti alloys are attractive for additive manufacturing as they offer high strength and toughness, with the ability to readily tailor properties through control of the phase fraction and morphology of precipitate phases. However, during additive manufacturing processes thermal cycling associated with repetitive layer-by-layer deposition can potentially promote unintended β-phase decomposition

The development of Al-Mg-Si-based alloys with advanced superplasticity and improved mechanical properties is an important task for further application of superplastic blow-forming technology in the production of complex-shape parts. The current study focuses on the influence of eutectic forming Ni and Fe and dispersoid forming Sc and Zr alloying elements on the microstructural evolution, superplastic