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Glass-ceramics have extensive industrial applications owing to their superior mechanical, optical and physicochemical properties compared to either glasses or ceramics. Herein, we leverage the concept of high entropy materials to broaden the available chemical compositions for tailoring the properties of glass-ceramics. Among various compositions explored, the high entropy glass 45SiO 2 -20Al 2 O 3 -15MgO-11Li 2 O-1.5TiO 2 -1.5ZrO 2 -2P 2 O 5 -2BaO-SnO 2 -CaO was identified as particularly promising, being easily cast with no pores and cracks. Furthermore, we successfully controlled the crystallization process to produce high entropy glass-ceramics (HEGCs) that range from highly transparent to highly opaque. The concurrent crystallization of γ-spodumene and cordierite led to exceptional mechanical properties such as high Vickers microhardness (10.37 GPa), compressive strength (541 MPa), and flexural strength (305 MPa). These findings not only showcase a novel approach to customizing the chemical composition of glass-ceramics, but also suggest the potential emergence of a new class of glass-ceramics. These materials hold great promise for dental, optoelectronics and energy-related applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Interatomic potentials based on the second nearest-neighbor modified embedded-atom method (2NN-MEAM) have been developed for Fe-V and Cr-V binary alloys. The structural, mechanical and thermodynamic properties of various stable and metastable phases in Fe-V and Cr-V binary systems were calculated by molecular dynamic (MD) simulation using the developed 2NN-MEAM potentials. A good consistency between the MD-calculated data and the experimental data or first-principles calculations was obtained. The potentials were further employed to predict several chemically complex intermetallic alloys (CCIAs) with stable B2 and L1 2 ordered structures in CoCrFeNiTiV system. Finally, this work pave the way to investigate the atomic scale physical metallurgy of V-containing and chemically complex intermetallic alloys and adjust their composition and microstructure to meet the specific requirements entailed in advanced applications. [ABSTRACT FROM AUTHOR]

This study aims at developing novel Full-Heusler high entropy intermetallic compounds (FH-HEICs). To this end, the formation of Heusler-type intermetallic structures and their thermal stability are studied in three systems with (CoFeNiCuV) 2 MnAl, Co 2 (FeMnNiCuTi)Al and Co 3 (FeMnNiCu)Al chemical compositions, where one sublattice composed of multi-component elements. The results indicated that (CoFeNiCuV) 2 MnAl crystallizes in a pure FH-HEIC type phase consisting of ordered L2 1 and disordered A2 structures, and it remains stable after 5 h annealing at 900 °C. Annealing could effectively suppress segregation of elements in (CoFeNiCuV) 2 MnAl, but it did not trigger substantial disorder-to-order phase transition. Co 2 (FeMnNiCuTi)Al crystallized in a mixture of B2 and FCC phases, in which the ordered B2 structure undergoes a transition to disordered A2 type structure upon annealing at 900 °C. On the other hand, Co 3 (FeNiMnCu)Al exhibited a A2+FCC two-phase structure in both as-cast and annealed states. (CoFeNiCuV) 2 MnAl exhibited higher microhardness value (589 HV) compared to Co 2 (FeMnNiCuTi)Al (474 HV) and Co 3 (FeMnNiCu)Al (417 HV) FH-HEICs, consisting with its higher degree of ordering. Finally, all the samples exhibited ferromagnetic behavior with relatively high magnetic saturation and coercivity in the range of semi hard magnetic materials. [Display omitted] • Full-Heusler high entropy intermetallic compounds (FH-HEICs) are developed. • (CoFeNiCuV) 2 MnAl FH-HEICs composed of ordered L2 1 and disordered A2 structures. • The microhardness of FH-HEICs are correlated with the degree of ordering in lattice structure. • FH-HEICs exhibited ferromagnetic behavior with relatively high magnetic saturation. • Entropy engineering is an effective route to improve functional properties of Heusler phases. [ABSTRACT FROM AUTHOR]

(NiCoFeCuMn)Zn 3 and (NbTaVNiTiFe)Al 3 high entropy intermetallic compound (HEIC) powders are fabricated by induction melting followed by ball milling. The fabricated (NiCoFeCuMn)Zn 3 HEIC powder possesses a single γ-brass D8 2 -type structure, while (NbTaVNiTiFe)Al 3 exhibits D0 22 HEIC phase along with Ni 4 Ti 3 and FeNi intermetallic inclusions. The microstructure of (NiCoFeCuMn)Zn 3 HEIC powder consists of a homogenous distribution of constituent elements. In the microstructure of (NbTaVNiTiFe)Al 3 , (TaNb)-rich and (FeNi)-rich regions are formed. A modified electronegativity parameter is proposed as a new indicator to design single high-entropy phases in ordered (A1A2A3 ... An)B m systems. The application of the prepared HEICs as precursor powders for detonation spraying (DS) is further examined. The results indicate that both powders can exhibit sufficient thermal stability during DS. The coatings exhibit sound bonding with substrate, and consist of lamellar microstructure with low porosities. It is predicted that HEICs, as a promising class of high entropy materials, are interesting candidates for a wide range of applications from coatings to catalysts. • Two novel high entropy intermetallic compounds (HEICs) were developed. • (NiCoFeCuMn)Zn 3 HEIC powder possesses a single γ-brass D82-type structure. • (NbTaVNiTiFe)Al 3 exhibits D022 HEIC phase along with Ni 4 Ti 3 and FeNi intermetallic inclusions. • Both powders exhibit sufficient thermal stability during detonation spraying. • HEICs are predicted as promising materials for coating applications. [ABSTRACT FROM AUTHOR]

High-entropy alloys (HEAs) provide a wide chemical composition window to design novel materials with tailorable properties for harsh environment, especially for high temperature oxidation applications. This paper studies both theoretically and experimentally the oxidation behavior of Al 0.25 CoCrFeNiMn and Al 0.45 CoCrFeNiSi 0.45 HEAs in the temperature range of 700 °C–1000 °C for 10 h in air atmosphere. Both samples exhibited a dendritic microstructure which underwent different phase evolution during 10 h of heating at 900 °C. Al 0.45 CoCrFeNiSi 0.45 HEA oxidized at 900 °C exhibited only about 0.1 mg/cm2 weight gain after 10 h, while this value was about 1 mg/cm2 for Al 0.25 CoCrFeNiMn HEA oxidized at 900 °C. The superior resistance to high-temperature oxidation of Al 0.45 CoCrFeNiSi 0.45 HEA was mainly ascribed to the formation of a protective Al 2 O 3 –SiO 2 rich oxide layer on the surface of the alloy. For Al 0.25 CoCrFeNiMn HEA, the formation of non-compact oxide layer containing transition elements could not provide sufficient protection against oxidation at elevated temperatures. Finally, a fair correlation between thermodynamic calculations and experimental analysis of oxidation behavior was realized. • Oxidation behavior of two HEAs were theoretically and experimentally investigated at 700–1000 °C. • An oxidation-resistant Al 0·45 CoCrFeNiSi 0.45 HEA was designed by tailoring chemical composition. • Al 2 O 3 –SiO 2 rich oxide layer provided superior resistance against high temperature oxidation. • Thermodynamic modeling showed fair agreement with experimental oxidation behavior. [ABSTRACT FROM AUTHOR]

In this study, NbTaTiVW refractory high entropy alloy (RHEA) particles were used as a modulator to tailor mechanical performance and wear resistance of WC based matrix body drill bits. A series of (WC) 100 (NbTaTiVW) 100-x (x = 0, 12, 20, 30 wt%) loose powder compacts was spontaneously infiltrated by Cu-Ni-Sn alloy binder under argon atmosphere. Microstructural studies indicated an adequate infiltration of WC/NbTaTiVW reinforcement phases with Cu-alloy binder without any micro or macro porosities. No intermetallic phases could be revealed at the WC/NbTaTiVW/binder interfaces owing to the high thermal stability of the reinforcement phases. The Charpy impact energy of the composites increased with increasing the content of RHEA particles, while the wear resistance was highly retained. The WC-20 wt% NbTaTiVW infiltrated composite exhibited 200% increase in the impact energy with only 10% increase in the wear rate. The analysis of fracture surface indicated that all the composites fail from cracks initiation and propagation in the WC particles. Finally, RHEA particles were introduced as proper and highly stable reinforcement particles for modulating mechanical properties of the WC-based matrix body drill bits. • Matrix body drill bits as a new era for the applications of RHEA powders is examined. • NbTaTiVW RHEA could be properly infiltrated by a Cu-alloy binder. • No intermetallic phases evolved at the WC/NbTaTiVW/binder interfaces. • WC-20 wt% NbTaTiVW infiltrated composite exhibited 200% increase in the impact energy. [ABSTRACT FROM AUTHOR]

The concept of entropy stabilized complex materials provides a novel direction for the design and engineering of breakthrough materials to be used in extreme environments and particularly in advanced nuclear reactors. While still in its infancy, the use of high entropy materials (HEMs) in nuclear fusion/fission reactors is extremely promising. This mini review first gives a brief introduction to advanced nuclear reactors and their material requirements. Next, it summarizes recent advances in irradiation behaviors of high entropy alloys (HEAs). Additionally, challenges and perspectives regarding the irradiation behavior of HEAs and potential research directions are deduced. [Display omitted] • State-of-the-art within irradiation behavior of HEAs is reviewed. • Several HEAs with superior irradiation resistance have been designed and fabricated. • Distinct interactions between cascades, defects and sinks in various HEA systems • New HECs such as MAX-HECs are enumerated as promising novel nuclear material. [ABSTRACT FROM AUTHOR]

High entropy alloys (HEAs) have provided a unique opportunity to design novel structure-function integrated materials through modulating chemical composition and tailoring microstructural features. In this study, a novel self-lubricating CoCrCu 1-x FeNi x (x = 0, 0.1, 0.3 and 0.5) HEA coating was in-situ prepared by laser cladding. The adequate amount of nearly pure copper segregated into the interdendritic regions could effectively smear the surface of the alloy and provide a Cu-rich protective oxide layer during dry sliding condition at an intermediate temperature of 400 °C. These findings serve as a proof of concept for the application of laser cladding as a high throughput process to rapidly fabricate self-lubricating HEA coatings through combining the intrinsic features of HEAs and additive manufacturing. Image 1 • A self-lubricating CoCrCu 1-x FeNi x HEA was designed by tailoring microstructural features. • A novel route for designing self-lubricating HEAs without the addition of solid-lubricating agents. • The mechanism of formation of Cu-rich protective oxide layer was outlined. • The wear resistance significantly increased upon the formation of oxide layer. [ABSTRACT FROM AUTHOR]

In this work, the microwave assisted aluminothermic reduction of molybdenite (MoS 2) was first demonstrated, and then the reaction was optimized using different processing parameters. A self-sustainable combustion front was readily induced in a compressed stoichiometric mixture of MoS 2 and Al using microwave ignition. However, the reduction reaction (3MoS 2 + 4Al = 3Mo + 2Al 2 S 3) could not be fully completed mainly due to the rapid progress of the combustion front and insufficient available Al to fully reduce MoS 2. A leaching process in HCl was also adapted to remove the Al 2 S 3 byproduct and unreacted aluminum. Moreover, the effect of compaction pressure, excess Al and mechanical activation was further investigated to optimize the aluminothermic reduction reaction. Adding excess Al over the stoichiometric ratio shifted the reaction toward producing more Mo metal with lower retained MoS 2. While the effect of compaction pressure on the reaction products was found to be negligible, it could affect the ignition temperature and the propagation rate of the combustion front. Mechanical activation had two crucial effects on the aluminothermic reduction of MoS 2 : decreasing the ignition temperature and increasing the reaction progression. A mechanically activated MoS 2 /Al powder mixture, which was prepared by 30 min ball milling with 0.5 mol excess Al and compressed at 70 MPa, exhibited the best overall efficiency for aluminothermic reduction of MoS 2 to produce Mo metal. • A feasible and readily scalable method for aluminothermic reduction of molybdenite is developed. • A self-sustainable combustion front could be induced in a compressed stoichiometric MoS 2 /Al mixture. • Mechanically activation decreases the ignition temperature and increases the reaction progression. • 0.5 mol excess Al and 30 min mechanically activation result in the best overall efficiency. [ABSTRACT FROM AUTHOR]