The nanoindentation tests of CoCrFeNiMn high entropy alloy prepared by mechanical alloying route have been performed. Pop-ins on loading curves have been characterized by their indentation load, depth and length. Locations of indents within the grains, grain sizes and their orientation were obtained by the Scanning Electron Microscope/Electron Back Scattered Diffraction analysis. The stress state under

The stress distribution in microregion close to the shell of core-shell particle reinforced metal matrix composites is studied by the finite element analysis in this work. It is found that the stress distribution of the composites is dependent on the elastic modulus of both shell and core phases as well as the difference between them. If the elastic modulus of the formed shell is larger than that of

A novel Ti2AlC particle and in-situ TiAl3 reinforced pure Al composites with different preparation temperature were fabricated by pressure-infiltration technique. The microstructure, phases and compressive strength of 45% Ti2AlC–Al system composites were studied. Compress test and XRD results reveal that the composite consisting 50% TiAl3 exhibits the best properties when the fabrication temperature

In the present study, a copper modified titanium alloy (Ti–6Al–4V–2.5Cu) was prepared by using vacuum arc re-melting and processed successfully by hot forging and rolling. The alloy was subjected to solution treatment (ST) at two temperatures, viz. 900 °C and 1010 °C followed by low temperature ageing at 500 °C. The weldments were fabricated from the alloy by using gas tungsten arc welding (GTAW) in

High entropy alloys (HEAs) have attracted great attention due to their impressive properties induced by the severe lattice distortion in comparison to the conventional alloys. However, the effect of severe lattice distortion on the mechanical properties in face-centered-cubic (FCC) and body-centered-cubic (BCC) structured HEAs is still not fully understood, which are critically important to the fundamental

The plastic flow behaviour of single crystals of the CoCrFeMnNi high-entropy alloy is shown to be greatly influenced by the twinning multiplicity on the stress-strain (σ(ε)) curves, the strain hardening coefficient Θ = dσ/dε, plasticity and fracture. It is shown that a maximum effect of strain hardening is obtained during the onset of twinning in two systems in the [1¯11]- and [1¯44]-oriented crystals

Bimetallic structures can combine the performance of dissimilar metal materials to meet the multifunctional requirement in industrial solutions. In this paper, steel-bronze bimetallic structures were fabricated via self-developed multi-material selective laser melting (SLM) equipment. In order to investigate the influence of laser power, scanning speed, and hatching space on the interfacial characterization

AlxMoNbTaTiV alloys are designed according to the binary phase diagrams and calculation of phase diagrams (CALPHAD). The phase formation and elemental segregation are predicted using the CALPHAD method. The effects of Al on microstructures, and mechnical properties of AlxMoNbTaTiV are investigated, which verified the results of calculated dendritic microstructure and BCC structure. The strengthening

The creep behavior of pure nanocrystalline (nc) fcc metals has not been studied above 200 °C because the nanoscale grains tend to grow at temperatures moderately above ambient. In this work, we study the creep of nanocrystalline Ni–W (nc Ni–W) up to 450 °C, near its thermal stability limit. A nanoindenter with the capability to heat both the specimen and the indenter tip addresses the issue of heat

The effect of Si and Sc on the evolution of the precipitates during aging in Al4.0Cu0.5 Mg alloys was investigated by means of microhardness tests and transmission electron microscope. The results show that Si can significantly refine the size of θ′ phases, because addition of Si introduces a considerable amount of small, uniformly dispersed Al–Cu–Mg–Si (Q) quaternary phases, which provides nucleation

The deformation behavior of an AlTiVNbZr0.25 high entropy alloy at 1073 K was investigated in creep in protective argon atmosphere at stresses of 100–560 MPa with and without changes. In the initial condition after annealing at 1473 K for 24 h the alloys was composed of B2 matrix phase and coarse Zr5Al3-type particles. During creep a limited amount of new Nb2Al-type sigma phase precipitates at the

Post-fabrication heat treatment, including solution treatment (at 520 °C for 1 h) followed by water quenching (WQ), air cooling (AC) and furnace cooling (FC), was performed on a selective laser melted AlSi10Mg alloy. The objective is to assess the effect of various cooling rates on the microstructure (specifically eutectic-Si morphology) and small-scale mechanical properties, measured by employing

This paper deals with the development of a five-step rapid manufacturing technique for iron scaffold fabrication based on micro-extrusion-based 3D printing and pressureless microwave sintering. Two different pore morphology structures were fabricated with similar strut and pore sizes. Further, the mechanical properties of the fabricated scaffolds were evaluated.

The current work compares the deformation behavior of CoCrFeMnNi and CoCrNi in the temperature interval between 295 K and 8 K through a series of quasi-static tensile tests. Temperature-dependent yield stress variation was found to be similarly high in these two alloys. Previous investigations only extended down to 77 K and showed that a small amount of ε-martensite was formed in CoCrNi while this

Thermal aging experiments on a 9Cr-ODS steel were carried out at 700 °C with a period from 100 up to 10000 h, and the effects on mechanical properties and microstructural evolutions were investigated. It was found that hardness and tensile properties exhibited negligible degradation by thermal aging. The mixed ductile and brittle fracture modes in the tensile specimens remained almost no change. Although

In the present work, the Fe-13Mn-8Al-(0.7, 1.2)C steels were subjected to different post-cold rolling annealing treatments in a temperature range of 800 to 1000 °C for 15 min to investigate the microstructural evolution and the mechanical properties. Both steels annealed at 800 °C consisted of fine austenite and ferrite grains along with intergranular κ-carbides formed by eutectoid reaction, which

In this study, the plastic flow and ductile fracture of three 6000-series aluminium alloys commonly used for crash components in the automotive industry are characterised experimentally and the observations are related to microstructural features. The three alloys are used in the cast and homogenised condition after artificial aging to temper T6 to ensure isotropic behaviour. Tension tests on smooth

In this study, CoCrFeNi high entropy alloy was successfully joined by friction stir welding (FSW) and the influences of welding process parameters on the microstructure and mechanical properties were studied. Three distinct zones, namely, the stir zone (SZ), thermo-mechanically affected zone (TMAZ), and base metal (BM), have been identified. The SZ showed an equiaxed microstructure because of the recrystallization

A supersaturated Al–Zn–Mg alloy was processed by dynamic plastic deformation (DPD) using a Split-Hopkinson pressure bar (SHPB) facility with strain range from 0.5 to 1.5 and then subjected to compressive testing at strain rates of 1 × 10−3–4 × 103 s−1. The results show that there is concurrent occurrence of grain refinement, increase in dislocation density and precipitation of fine precipitates in

Strain rate sensitivity (SRS) of a face-centered cubic (fcc) CoCrFeNi high-entropy alloy (HEA) with grain sizes ranging from 57 μm to 45 nm was investigated using nanoindentation, and was compared with those reported for conventional fcc metals. Experimental results show pronounced grain boundary strengthening in the HEA. Estimated values of the SRS parameter, m and activation volume, V*, indicate

Heterogeneous microstructure and unpredictable porosity distribution in Al–Si high-pressure die-castings give rise to a significant variation in their mechanical properties. This study investigated the influence of porosity distribution, volume of the largest pore, eutectic phase morphology and Mn-containing intermetallics on the tensile properties of Al–Si–Mn–Mg high-pressure die-castings. The as-cast

Ni-free Ti-based shape memory alloy with superior superelasticity is promising and attractive for biomedical applications. In this study, Ti-18Zr-12.5Nb-2Sn (at.%) alloy fibers were prepared by rapid solidification method and then the effect of various heat treatments on phase constitutions, microstructures, mechanical properties, and superelasticity was investigated by means of X-ray diffraction (XRD)

Spheroidization and dynamic recrystallization (DRX) mechanisms of a Ti-55511 alloy during hot compression in α+β region is investigated. It is found that the spheroidization of lamellar α phases and DRX of β phases, which are obviously influenced by deformation conditions, are the main softening mechanisms. The spheroidization fraction of lamellar α phases first increases with the raised temperature

The thermo-mechanical fatigue (TMF) behaviors and corresponding damage mechanisms of Al-Si piston alloy were investigated in the temperature range of 120∼425 °C under different constraint factors (η). The TMF hysteresis loops exhibit asymmetrical, because the yield strength and elastic modulus decrease significantly with the increasing temperature. Taking the phase angles into consideration, the mean

In this paper, the deformation, fracture and damage behavior of SiCp/Al composites are studied by experiments and finite element analysis. The crack cracking process of the material was observed by in-situ tensile test, it was found that the composite first produced microcracks near the particles, and the cracks mainly spread to depth and then to both sides. It is determined by a tensile test that

This work studied the microstructure, superelastic and mechanical performances of a high Zr-containing Ti–40Zr–8Nb–2Sn (at.%) shape memory alloy aged at 300 °C for 1 h. Nanodomains and quite fine nano-scaled ωiso phases with 2.1–2.9 nm wide and 2.9–4.4 nm long were formed in the aged alloy. The aged alloy in this study exhibited excellent superelasticity with a large total recovery strain of 7.1%,

This work focusses on the link between microstructure and creep properties for heat-resistant austenitic alloys with high aluminum content (3–5 wt %). An emphasis was put on the coupling of thermodynamic simulations, microstructural characterizations by scanning electron microscopy and transmission electron microscopy, and creep testing. The phase predictions performed by the calculation of phase diagrams

Influences of solution temperature and subsequent cooling rate on microstructures and room temperature tensile properties of near α-TA19 alloy (Ti-6Al-2Sn-4Zr-2Mo-0.1Si) manufactured by laser metal deposition were investigated. The results show that after the solution and aging treatment, fine Basketweave structure of the as-fabricated TA19 alloy was transformed into Widmannstatten structure for the

The Mg93.72Gd5.85Y0.43 alloy with columnar grains and preferred orientation of [224(_)5] was selected in this paper, and its deformation mechanism was investigated by room-temperature tensile test, quasi-in-situ observation and Electron Back Scatter Diffraction (EBSD). The results showed that all the columnar grains had the “soft” orientation ([224(_)5]) for both basal slip system and {101(_)2}

Multilayered aluminum composites (ARB6-2N/4 N) with alternating layers of commercially purity aluminum (2N–Al) and high-purity aluminum (4N–Al) were fabricated by six cycles of accumulative roll bonding (ARB) processing. The ARB processed specimens were annealed at different temperatures. It was found that heterogeneous lamellar microstructures composed of fine-grained 2 N (hard) layers and coarse-grained

Recent studies suggested that nanotwinned metallic materials can exhibit a good combination of high strength and high ductility. However, few studies examined the strength and ductility of nanotwinned alloys under hydrogen atmosphere. In this study, nanotwins are introduced in a TWIP (twinning-induced plasticity) steel by application of high-pressure torsion (HPT) followed by annealing. The nanotwinned

Microstructure and mechanical property of 42CrMo steel after electropulsing (EP) treatment were studied. The average prior austenite grains (PAGs) size was refined to 2.9 μm after EP austenitization, compared with conventional austenitization. EBSD test results indicated the size of sub-grains with high angle boundaries was refined from 1.53 μm to 0.53 μm. The quenched 42CrMo steel with ultrafine PAGs

Nanodiamond reinforced silver matrix nanocomposites with different nanodiamond content are produced from pure silver and nanodiamond powders by a combination of two severe plastic deformation methods, ball-milling and high-pressure torsion (HPT). The ball milling parameters are varied to improve the distribution of the nanodiamonds in the powder blends. An optimized processing route combining both

The present work contributes to a better understanding of the effect of stress multiaxiality on the creep behavior of single crystal Ni-base superalloys. For this purpose we studied the creep deformation and rupture behavior of double notched miniature creep tensile specimens loaded in three crystallographic directions [100], [110] and [111] (creep conditions: 950 °C and 400 MPa net section stress)

The fracture anisotropy of ultrafine grained pure Cu processed by eight passes of equal channel angular pressing in route BC was investigated based on elastic-plastic fracture mechanics. For different crack planes and different crack propagation directions, both the global fracture initiation toughness measured by JIC and KIC and the crack growth toughness represented by the non-dimensional tearing

A novel medium Mn steel of composition Fe-12Mn-4.8Al-2Si-0.32C-0.3V was manufactured with 1.09 GPa yield strength, 1.26 GPa tensile strength and 54% elongation. The thermomechanical process route was designed to be industrially translatable and consists of hot and then warm rolling followed by a 30 min intercritical anneal. The resulting microstructure comprised of coarse elongated austenite grains

Mechanical responses of nanostructured twinning induced plasticity (TWIP) steels have attracted attention owing to their ultra high strength and ductility. A set of molecular dynamics simulations were carried out to characterize and track the atomic structure of Fe–22Mn (wt. %) nanocrystalline TWIP steel during reverse loading (tension-compression). The results show that intrinsic stacking faults and

The present study addresses the damage evolution mechanism in precipitation-strengthened Fe–Ni–Cr-based steel (SUH 660) at ambient temperature in air. Specifically, damage quantification and associated microstructure characterization were performed. The damage initiation sites were inclusion and grain boundaries impinging dislocation slip. The early stage of damage evolution was observed before necking

The grain orientation dependence of the deformation-induced forward fcc→hcp and reverse hcp→fcc martensite transformation of a FeMnSi-based shape memory alloy was studied by in situ neutron diffraction during cyclic loading. A deformation-induced fcc→hcp transformation is observed during tensile straining to +2%. The hcp martensite phase that forms under tension partially reverts to fcc austenite upon

3D printed technique of selective laser melting (SLM) has attracted great attention in fabricating bulk metallic glass (BMG) due to its superiority on fabrication of large-sized BMGs with desirable geometries. However, compared to traditional casting BMGs, 3D printed BMGs present brittleness due to annealing effect in 3D printing process. Rejuvenation treatment in supercooled liquid state was expected

Understanding the relationship between strain rate and deformation behavior in micro-sized amorphous alloys is key to optimizing mechanical properties for emerging flexible skin smart sensors and engineering applications. The tensile behavior of Co68.15Fe4.35Si12.25B15.25 amorphous fiber was investigated over a wide range of strain rate of 5 × 10−5 s−1–1 × 10-1 s−1 at room temperature (RT) by an in-situ

In order to study the correlation between microstructure, strength and fracture toughness (KIC) and optimize the strength-KIC combination, BASCA (β annealing slow cooling plus aging) and STA (α/β solution treatment plus aging) heat treatment followed by near β forging is conducted to obtain a variety of multiscale lamella structure and Bi-modal structure. The results show that multiscale lamella structure

Here an inverse gradient structure (IGS) is processed by induction heat treatment on ultrafine-grained substrate, and a multi-gradient structure (MGS) is gained by surface mechanically peening treatment on IGS material. The grain size distributions of coarse-ultrafine and nanostructure-coarse-ultrafine gradient from surface to interior are identified in IGS and MGS materials, respectively. Gradient

The quantitative effects of pre-treatments, namely pre-stretching and natural ageing (NA), on the precipitation sequence, precipitation kinetics and mechanical properties of an Al–Cu–Li–Mg–Ag alloy during artificial ageing were systematically investigated, aiming to elucidate the mechanisms by which these effects proceed. At the early ageing stage, pre-stretching could inhibit the formation of GP zones

Liquid-phase sintering is advantageous compared to solid-state sintering in manufacturing ceramic composites including lightweight armors. The crystalline phases formed from the liquid phase affect the mechanical properties of the material, and thus, to the best of our knowledge, their effect on the ballistic behavior need to be understood. In this paper, the correlation between mechanical properties

2219 Al alloy has been used to manufacture the launch vehicle storage tank transition ring, but the large ring obtained in conventional manufacturing processes still suffers from severely agglomerated coarse second phase particles and poor mechanical properties. An improved process (forging at 510 °C with 20% deformation and at 240 °C with 50% deformation, then rolling at 240 °C with 30% deformation

In this study, the microstructural evolution and strengthening mechanism of deformation-processed CoCrFeCuNi and CoCrFeCu1.71Ni were studied. Segregation and phase separation into dual fcc phases was found to be thermodynamically stable even after homogenizing annealing at 1273K. Dual fcc phase structure with elongated Cu-rich filaments developed by deformation processing and elongated dual-phase structure

Selective laser melted (SLM) AlSi10Mg alloy was subjected to high cycle fatigue test to elucidate the effect of microstructural characteristics and sub-microscopic defects in its dynamic behaviour. The microstructure of the processed materials revealed scan tracks on the scanning surface and solidified melt pool/melt pool tracks on the surface in the build direction. The processed material exhibits

Effects of Sb modification on the eutectic microstructure and tensile properties of hypoeutectic Al–11Mg2Si alloy were systematically investigated in this work. Eutectic Mg2Si phase in hypoeutectic Al–11Mg2Si alloy was successfully refined from the long rod-like structure into fine spherical morphology when introducing 0.2 wt% Sb, whereas 1.0 wt% Sb reversely led to the formation of coarse eutectic

AZ91 alloy, the most widely used Mg casting alloy, exhibits low strength/ductility and weak energy absorption, which is a function of its large grain size and the presence of a coarse and continuous network of β-Mg17Al12 intermetallic compounds. This work demonstrated that friction stir processing (FSP) enables enhancement of strength and energy absorption capability of AZ91 alloy. The influence of

An extensive study of the different methods able to measure material creep properties in indentation is proposed. A systematic comparison of the fast creep, long-term creep, constant strain rate and long-term relaxation tests is performed on amorphous selenium. Even though measured apparent activation energy and strain rate sensitivities are very similar for all tests, a discrepancy is highlighted