Activation of the β relaxation of metallic glasses is usually related to the activation of the structure units which correlates with the activation of shear transformation zones. In the present work, a pronounced slow β relaxation behavior was observed around ambient temperature in (La25Ce75)65Al11Co24 metallic glass. Based on the compression tests at 223 K and 300 K, the results demonstrated that

We investigate the microstructure and deformation substructure evolution in an additively manufactured 1.8 at.% N-doped FeCoNiCr high-entropy alloy (HEA) by means of correlative electron backscatter diffraction (EBSD) and electron channeling contrast imaging (ECCI). The combinational use of EBSD and ECCI uncovers hierarchal structures of the HEA at multiple length scales, which consist of a bimodal

The aim of the present work was to study the influence of Gd microaddition on the sequence and temperatures of phase transformations as well as on the microstructural evolution and properties of a new six-component TiAl-based alloy Ti-44.5Al-2V-1Nb-xZr/yCr-(0 … 0.1)Gd (at.%) with variable Zr (x = 0.5–1.5 at.%; eq. 1.2–3.5 wt%) and Cr (y = 1.5–2.5 at.%; eq. 2.0–3.5 wt%) content in the as-cast condition

Relaxation behaviors of highly rejuvenated Zr50Cu40Al10 bulk metallic glass was investigated using synchrotron X-ray scattering coupled with differential scanning calorimetry. The relaxation of rejuvenated volume is found to correspond to a marked exothermic event prior to the glass transition. High-energy synchrotron X-ray measurements of the structure factor show that annihilation of rejuvenated

Powder metallurgy (PM) Ti–22Al–25Nb (at.%) alloy was prepared by spark plasma sintering under the conditions of 950 °C/80 MPa/10 min. Isothermal unidirectional compression experiments of the PM Ti–22Al–25Nb alloy were completed on the Gleeble-3500 thermal–mechanical simulator at temperature and strain rate ranges of 920 °C–1100 °C and 0.001–10s−1, respectively, and a total height reduction of 50%.

Nacre, a biomimetic model system with multiscale architectures and adjustable components, has always inspired researchers to create novel materials with advantages such as light-weight, exceptional strength and toughness. Inspired by nature, nacre-like bionic Ti2AlC/TiAl–Ti6Al4V laminated composite sheets had been designed and fabricated by spark plasma sintering technology using commercial Ti6Al4V

In this paper, the ultrasonic hammering treatment is applied to the lightweight entropic alloy Al80Li5Mg5Zn5Cu5, contributing to the modification of coarse microstructures and the improvement of mechanical properties. The effects of ultrasonic hammering on the microstructures and mechanical properties of Al80Li5Mg5Zn5Cu5 are elaborately studied, and the formation of sub-grains is thoroughly analyzed

In this study, a new CuZrAl ternary bulk metallic glass (BMG) with glass forming ability (GFA) of 10 mm in diameter was fabricated. The GFA of the BMG was discussed based on the suppression of the competing crystal phase and the efficient dense packing of the constituting atoms. Compression testing showed that the CuZrAl ternary BMG has good true plastic deformation of 11.7%, whereas its adjacent composition

In this work, the influences of Fe, Mn and Y with various contents on microstructural evolution and mechanical properties of hypoeutectic Al–7%Si alloy were investigated by microscopy technology and tensile test. The results showed that the complex addition of Al–20%Si-2.5%Fe–2%Mn master alloy and rare earth Y have much better refining effect of need-like eutectic Si and coarse α-Al dendrites than

Silicides and especially Mg2X (X = Si, Sn, Ge) are considered as attractive thermoelectric materials, which are capable of an efficient heat to electricity energy conversion. They have low density, abundant and affordable raw constituents, and good mechanical properties. Yet, the synthesis of such Mg- based compounds is usually very challenging due to the reactivity, volatility and oxidation tendency

Selective Laser Melting (SLM) is an additive manufacturing technology commonly applied for direct fabrication of complex-shaped parts from metal powders. In the current paper encapsulated hot isostatic pressing (HIP) is applied to improve the structure and mechanical properties of the NiAl intermetallic alloy part produced by SLM. It was found that HIP treatment of SLM samples consolidated the material

The europium-based intermetallic compounds EuAgZn, EuAgCd, EuPtZn and EuAuCd were synthesized and their magnetic properties and magnetocaloric performances were systematically studied. EuAgZn and EuAgCd compounds crystallize in a KHg2-type structure belonging to space group Imma, whereas EuPtZn and EuAuCd crystallize in a TiNiSi-type structure belonging to space group Pnma. The four compounds contain

The knowledge of phase diagram is theoretical principle for compositional design. Since Ti and Al are important alloying elements for Nb–Si alloys, and Nb and Si are important alloying elements for Ti–Al alloys, Nb–Ti–Si–Al phase equilibria is prerequisite for optimal microstructural design of both Nb–Si and Ti–Al systems. In this work, key alloys were selected firstly according to calculated isothermal

TiAl-based composites reinforced with different weight fractions of Al2O3 have been successfully synthesized by hot-pressing using the pre-alloyed Ti–45Al–7Nb-0.2B and Nb2O5 powders. The microstructures, mechanical and tribological properties of composites were examined. The as-sintered TiAl composites mainly consist of γ-TiAl phase, α2-Ti3Al phase, γ/α2 lamellar colony, TiB2 particles and Al2O3 particles

Three alloys with composition range of Ti-(25–35)Al (atomic %) were in-situ investigated using neutron diffraction to clarify the phase stability and equilibria in the Ti-rich part of the Ti–Al binary system. The phase transformation sequences of these three alloys were identified based on the neutron diffraction results and differential scanning calorimetry. No superstructure diffraction of β0 has

In this study, catalysts for CO oxidation were prepared through in-situ activation of Ce50Ni50-xAux intermetallic compounds and characterized; these included Ce50Ni50 and Ce50Ni45Au5. Ribbon samples of intermetallic compounds were fabricated by single-roller melt spinning and then ground into powders for subsequent analysis. XRD patterns of the compounds were indexed as orthorhombic symmetry and no

An equimolar hexahydroxy AlCoCrCuFeNi high-entropy alloy (HEA) was produced by selective laser melting (SLM) gas-atomized powders, with emphasis on investigating its microstructure and properties. SLM printed AlCoCrCuFeNi HEA shows high crack sensitivity with faced centered cubic (FCC) and body-centered cubic (BCC) phases. High-angle grain boundary, segregation of Cu element and the misfit between

γ′ phase (AlNi3) particles' precipitation behavior in the Cu–15Ni-xAl alloys (wt.%, x = 0, 1, 2, 3 and 4) ageing at different temperature was systematically discussed with the help of Calphad method. With fixed ageing temperature, when Al content increases from 1 wt% to 4 wt%, the γ′ phase particles transform from a few microns to dozens of nanometers in size. The increasing Al content was proven to

In this study, a fine fully lamellar structure was formed with only a stepped-cyclic heat treatment process without hot working. The cast structure before the heat treatment contained large segregation areas and a coarse columnar structure (>1000 μm). Thus, the mechanical properties at room temperature were not ideal. In contrast, the segregation in the microstructures after the heat treatment was

The rare-earth and transition-metal based polycrystalline, binary compound DyIr3 has been synthesized successfully and is found to form as a macroscopic coexistence of AuBe5 and AuCu3-type polymorphic structures. The analysis of dc magnetization and specific heat data reveals that among the two polymorphic phases, the AuBe5-type phase exhibits ferromagnetic ground state below 22 K, while AuCu3-type

In the present work, a novel technique has been introduced to obtain an aluminide coating by casting process and subsequent heat treatment. To do so, the aluminum sheet was placed at the bottom of a copper mold, then HH309 SS melt was poured into the mold. This technique was named Cast-Aluminizing (CA). The CA samples were heat-treated at the temperature range of 900–1050 °C for 0.5–5 h. The FE-SEM

In order to evaluate the impact of an oxidation resistant coating on the structural performance of a Mo-9Si-8B alloy tensile creep experiments were conducted at 1200 °C. After a plastic strain of 6% the creep rates of the coated samples compared favorably with the reported values for uncoated samples. Moreover, the coating structure was maintained during creep deformation and the coating exhibited

High-entropy alloys with a superalloy-like microstructure show excellent mechanical properties at elevated temperatures. In this paper, a multi-phase high-entropy alloy CrMnFeCoNiAl0.75 was developed. Based on the microstructure characterization by XRD, SEM, TEM and 3D-APT, it was found that the alloy was composed of FCC phase, BCC phase, and B2 phase. The mechanical properties evaluation showed that

In order to reveal the relationship between microstructure evolution and mechanical properties of CoCrFeMnNi high entropy alloys (HEAs), samples were prepared by directional solidification process with different cooling rates. The solidified phases of CoCrFeMnNi HEA including two different FCC phases, CoCrFeNi3-enriched FCC1 phase and MnNi-enriched FCC2 phase. When the cooling rate increased from 30 × 10−3K/s

In this study, low-cost AlCoCrFexNi (x = 1.5, 2.5) high entropy alloy (HEA) coatings were prepared by laser cladding and their microstructural evolutions, mechanical properties and wear behaviors were investigated. Both Fe–Cr rich disordered BCC(A2) phase and Al–Ni rich ordered BCC(B2) phase were identified in these coatings. At x = 1.5, the coating consisted of B2 matrix and nano-scale A2 precipitates

We evaluated the suitability of Fe40Co30Ni30 as a precursor for Fe-rich FeCoNi-based high-entropy semi-hard magnets. Mechanically alloying the metal powders 40 at.% Fe, 30 at.% Co, and 30 at.% Ni for 12 h effected micron-size Fe40Co30Ni30 powder comprised of nanocrystalline γ phase. Fe40Co30Ni30 evinced semi-hard magnetic properties at room-temperature—saturation magnetization (MS) ~146 Am2/kg and

Structural heterogeneity has been proposed as a key intrinsic feature and mechanism underline unique properties and dynamic behavior of metallic glasses; however, it is still challenging in precisely describing and effectively characterizing the atomic-scale heterogeneity in metallic glasses. In this work, we employed the Meissner effect of superconductivity in magnetic susceptibility measurements

In this work, we investigated the three-point bending fatigue behavior of a brittle Ti32.8Zr30.2Ni5.3Cu9Be22.7 MG (ZT3) combined with damage morphology observation using scanning electron microscope. It is found that the brittle ZT3 MG possesses the excellent fatigue resistance with the fatigue endurance limit of ~527 MPa based on stress amplitude, and the fatigue ratio of ~0.29 termed as fatigue endurance

The high temperature compressive characteristics of relatively light weight AlCoCrFeNi HEA were investigated via compression tests in a wide deformation temperature (T) range of 1073–1373 K and strain rate (ε˙) range of 10−3–1 s−1. Hot deformation led to the phase constitution transformation from the disorder BCC (A2) + order BCC (B2) at the room temperature to FCC + A2+ B2 +σ at 1073 K and 1173 K

The Nb3(Al1-xSnx) superconductors (x = 0.05, 0.15, 0.25, 0.35) were prepared by mechanical alloying and subsequent low-temperature sintering. It was found that the critical current density (Jc) of the obtained Nb3(Al1-xSnx) sample is enhanced significantly compared to undoped Nb3Al prepared using the same method. The maximum value of the Jc reaches up to 5.10 × 104 A·cm−2 (4.2 K, 5 T) for Nb3(Al0.85Sn0

Microstructural characteristics and hardness of Cr-coated Zr702 sheet after the laser surface treatment (LST) were characterized and investigated by combined use of electron backscatter diffraction, electron channeling contrast imaging, energy dispersive spectrometry and hardness measurement. Results show that after the LST processing at 100 W, three zones with different microstructural characteristics

Here, we report on an economical, viable, one-step method for fabrication of Higher Manganese Silicide MnSi1.75 (HMS). Fabrication of the HMS was followed by spark plasma sintering (SPS) at different temperatures (850, 900, 950 and 1000 °C), after which the thermoelectric and mechanical properties were investigated. It was found that the electrical conductivity significantly increased with increasing

The structure and compositions of spinodal phases in Alnico8 alloy isothermally treated at 830 °C under external magnetic field (Hext) up to 10 T were investigated by transmission electron microscopy (TEM). Under ultra-high magnetic field (10 T), the spinodal structure of Alnico8 alloy presents interesting diversity for the shapes of α1 phase particles, namely, Π-shape, H-shape and Ш-shape apart from

Shape recovery in conventional shape memory alloys is typically a relatively slow process showing low heating rate sensitivity. In contrast to that, some shape memory alloys such as Ni–Fe–Ga–Co, Cu–Al–Ni, Cu–Al–Fe–Mn can exhibit the effect of burst-like shape recovery when the original shape is restored almost instantaneously in a very narrow temperature range. Here we report on an abnormal stress-strain

The refractory high entropy alloy (RHEA) has shown great potentials for high temperature applications beyond modern Ni-based superalloy. However, its oxidation behaviours are rarely reported and understood. In this work, the oxidation behaviours of a novel RHEA “NV1”, Cr-17.6Al-20.3Mo-15.2Nb-2.9Si-13.4Ta-5.4Ti (in at%), were examined at 1200, 1300, and 1400 °C up to 100 h. At 1200 °C, the oxidation

Intermetallic compounds and micro-structures in Ni–Mn–In alloy system were investigated with transmission electron microscopy, selected-area and nano-beam electron diffraction, and energy-dispersive x-ray spectroscopy. Together with two types of Heusler phases, a decagonal quasicrystalline phase and a structurally related crystallite were found in the Ni–Mn–In system. As is well-known, most of the

Ni-Mn-based metamagnetic shape memory alloys have been extensively studied due to their multifunctional properties including magnetocaloric effect (MCE), magnetoresistance effect, and magnetic-field-induced strain. However, the large intrinsic thermal hysteresis of these alloys sets a limit on further development for practical applications. Here, with a few atomic percent Al substitution, we greatly

The microstructures and room temperature tensile properties of as-cast and directionally solidified AlCoCrFeNi2.1 eutectic high-entropy alloy were investigated using OM, SEM, EDS, TEM and tensile tests. The microstructure of as-cast alloy, including the well-aligned lamellar structures, the radial emanating lamellar structure and mesh-like structure, consists of NiAl-rich (B2) and CoCrFeNi-rich (L12)

A series of Zr–Ti–Y–Al–Cu–Ni–Co–Fe complex multi-component bulk metallic glasses (CMBMGs) were designed using multi-substitution strategy in Zr55Cu35Al10, Zr60Cu30Al10 and Zr60Cu28Al12 BMGs, and their crystallization and corrosion behaviors were systematically investigated. It is found that, CMBMGs have higher complexity in crystallization compared to their ternary counterparts, and well-dispersed

High temperature titanium alloy/Ti-43Al-9V metal-intermetallic laminate composite was successfully fabricated by hot-pack rolling. The titanium alloy exhibits a lamellar structure and the TiAl alloy consists of B2 phase and elongated γ phase. Due to the low rolling and annealing temperature, the TiAl alloy shows a low extent of dynamic recrystallization (69.3%) and a high dislocations density (17%)

Tuning energy state of metastable bulk metallic glasses (BMGs) is well known significant for understanding their glass nature and controlling their performances. Using a newly developed ultrasonic vibration precompression (UVPC) method, fast rejuvenation is achieved in a Zr-based BMG in seconds. The rejuvenated BMG has more heterogeneous structure and largely improved plasticity. The underlying mechanism

Gd3-xTbxCo compounds with x = 0, 0.25, 0.5, 1, 1.5, 2, 2.5 and 3 were investigated using structural and magnetic methods. The lattice parameters, and the location of 4c and 8d Wyckoff sites occupied by Gd, Tb, and Co atoms, in an Fe3C–orthorhombic type of structure, were refined by the Rietveld method. The magnetic ordering temperature changes linearly with Tb content. The magnetocaloric effect (MCE)

Zr65.5-xHfxNb3Cu13Ni11Al7.5 (x = 0.0, 0.5, 1.0, 1.5 and 2.0 at.%) bulk metallic glasses (BMGs) were successfully prepared by copper mold casting. The effects of minor Hf addition on the mechanical properties and fracture mechanisms were investigated. The quasi-static compressive mechanical properties of Zr65.5-xHfxNb3Cu13Ni11Al7.5 alloys were significantly improved by Hf addition. The optimum compressive

AlxFeNiCrCo (0≤x≤1.5) high entropy alloys (HEA) have been studied both experimentally and theoretically, considering the multi-phase character of investigated samples. Magnetic properties of these alloys (ordering temperatures and average magnetic moments) were determined from magnetization measurements (VSM), being found strongly dependent on Al content. Decomposition of this HEA system into phases