摘要：high-entropy alloys(HEAs),which were introduced as a pioneering concept in 2004,have captured the keen interest of nu-merous ***,in this context,can be perceived as representing disorder and *** contrast,elemental composi-tions within alloy systems occupy specific structural sites in space,a concept referred to as *** accordance with Shannon entropy,structure is analogous to ***,the arrangement of atoms within a material,termed its structure,plays a pivotal role in dictating its *** addition to expanding the array of options for alloy composites,HEAs afford ample opportunities for diverse structural *** profound influence of distinct structural features on the exceptional behaviors of alloys is underscored by numer-ous *** features include remarkably high fracture strength with excellent ductility,antiballistic capability,exceptional radi-ation resistance,and corrosion *** this paper,we delve into various unique material structures and properties while elucidating the intricate relationship between structure and performance.

摘要：high-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and *** studies on the deformation mech-anisms of HEAs can guide microstructure control and toughness design,which is vital for understanding and studying state-of-the-art structural *** X-ray and neutron diffraction are necessary techniques for materials science research,especially for in situ coupling of physical/chemical fields and for resolving macro/microcrystallographic information on ***,several re-searchers have applied synchrotron X-ray and neutron diffraction methods to study the deformation mechanisms,phase transformations,stress behaviors,and in situ processes of HEAs,such as variable-temperature,high-pressure,and hydrogenation *** this review,the principles and development of synchrotron X-ray and neutron diffraction are presented,and their applications in the deformation mechanisms of HEAs are *** factors that influence the deformation mechanisms of HEAs are also *** review fo-cuses on the microstructures and micromechanical behaviors during tension/compression or creep/fatigue deformation and the application of synchrotron X-ray and neutron diffraction methods to the characterization of dislocations,stacking faults,twins,phases,and intergrain/interphase stress *** on future developments of synchrotron X-ray and neutron diffraction and on research directions on the deformation mechanisms of novel metals are discussed.

摘要：Fatigue failures cost approximately 4% of the United States' gross domestic product(GDP). The design of highly fatigue-resistant materials is always in demand. Different from conventional strategies of alloy design, high-entropy alloys(HEAs) are defined as materials with five or more principal elements, which could be solid solutions. This locally-disordered structure is expected to lead to unique fatigue-resistant properties. In this review, the studies of the fatigue behavior of HEAs during the last five years are summarized. The four-point-bending high-cycle fatigue coupled with statistical modelling, and the fatigue-crack-growth behavior of HEAs, are reviewed. The effects of sample defects and nanotwins-deformation mechanisms on four-point-bending high-cycle fatigue of HEAs are discussed in detail. The influence of stress ratio and temperature on fatigue-crack-growth characteristics of HEAs is also discussed. HEAs could exhibit comparable or greater fatigue properties, relative to conventional materials. Finally,the possible future work regarding the fatigue behavior of HEAs is suggested.

摘要：Microstructures and mechanical properties of dual-phase AlxCrMnFeCoNi (x=0.4, 0.5, 0.6, at.%) alloys were investigated. Thermomechanical processing leads to a microstructural evolution from cast dendritic structures to equiaxed ones, consisting of face-centered cubic (fcc) and body-centered cubic (bcc) phases in the two states. The volume fraction of bcc phase increases and the size of fcc grain decreases with increasing Al content, resulting in remarkably improved tensile strength. Specifically, the serrated flow occurring at the medium temperatures varies from type A+B to B+C or C as the testing temperature increases. The average serration amplitude of these Al-containing alloys is larger than that of CoCrFeNiMn alloy due to the enhanced pinning effect. The early small strain produces low-density of dislocation arrays and bowed dislocations in fcc grains while the dislocation climb and shearing mechanism dominate inside bcc grains. The cross-slip and kinks of dislocations are frequently observed and high-density-tangled dislocations lead to dislocation cells after plastic deformation with a high strain.

摘要：The micro-cracking behaviors of two high-entropy alloys(HEAs) of the FeMnCoCrNi family prepared by selective laser melting were systematically studied. Residual stresses were also analyzed by X-ray diffraction technique. Results show that the equiatomic FeMnCoCrNi HEAs with a relatively stable single-phase face-centered cubic(FCC) structure suffered from micro-cracking with residual tensile stress after laser melting. In contrast, the metastable non-equiatomic Fe MnCoCr HEAs with reduced stacking fault energy are free of micro-cracks with residual compressive stress at various volumetric energy densities(VEDs). The displacive transformation from the FCC matrix to the hexagonal close-packed(HCP) phase during cooling prevents the micro-cracking via consuming thermal stress related internal energy. Further, the displacive transformation during tensile deformation contributes to the higher strength and ductility of the metastable dual-phase HEA compared to that of the stable single-phase HEA. These findings provide useful guidance for the design of strong, ductile, and crack-free alloys for additive manufacturing by tuning phase stability.

摘要：high-entropy alloys(HEAs)have been widely studied due to their unconventional compositions and unique physicochemical properties for various ***,for the first time,we propose a surface strain strategy to tune the electrocatalytic activity of HEAs for methanol oxidation reaction(MOR).high-resolution aberration-corrected scanning transmission electron microscopy(STEM)and elemental mapping demonstrate both uniform atomic dispersion and the formation of a face-centered cubic(FCC)crystalline structure in Pt Fe Co Ni Cu *** HEAs obtained by heat treatment at 700℃(HEA-700)exhibit 0.94%compressive strain compared with that obtained at 400℃(HEA-400).As expected,the specific activity and mass activity of HEA-700 is higher than that of HEA-400 and most of the state-of-the-art *** enhanced MOR activity can be attributed to a shorter Pt–Pt bond distance in HEA-700 resulting from compressive *** nonprecious metal atoms in the core could generate compressive strain and down shift d-band centers via electron transfer to surface Pt *** work presents a new perspective for the design of high-performance HEAs electrocatalysts.

摘要：high-entropy alloys(HEAs)contain multiple principal alloying elements,but usually with simple crystal *** are structurally complex phases,but are generally dominated by only one ***,nearequiatomic high-entropy quasicrystals have rarely been reported because they are difficult to prepare experimentally and predict ***,the preparation and crystal structures of near-equiatomic high-entropy quasicrystals have drawn much *** report a quinary decagonal quasicrystal(DQC)with near-equiatomic alloying elements in Al20Si20Mn20Fe20Ga20 melt-spun ribbons,which is the first to our ***,the structural features of the DQC are characterized in *** configurational entropy of both the alloy and DQC satisfies the entropy-based criterion for HEAs,suggesting a high-entropy *** findings provide a new strategy to develop high-entropy quasicrystals.

摘要：氢能作为一种清洁能源,已成为全球能源战略的重要组成部分,也是实现全球“碳中和”的必要途径之一.在可再生电力的驱动下,水电解法有望成为实现“零碳”排放的一种理想的长期制氢方法.与传统合金相比,高熵合金由于其独特的结构特征,包括占位无序和晶格有序,可提供更多的催化活性位点.它们在水解催化剂领域具有广泛的应用前景.本文综述了电解水的机理、水解过程中高熵合金的催化原理,以及高熵合金作为电解水催化剂的最新研究进展.总结了新型高熵合金设计方面存在的难点及其应用潜力,重点讨论了高熵合金在水解催化过程中表面形态和催化活性之间的联系.最后归纳了高熵合金的组成调控及其在水电解等新兴领域的可能应用前景.

摘要：高熵合金近年来在电催化领域广受关注.由于其四大“核心效应”,即高熵效应、晶格畸变效应、迟滞扩散效应和鸡尾酒效应,高熵合金在诸多电催化反应中展现出了优异的活性和选择性.然而在已报道的文献综述中,有关其优异性能的理解以及合理设计的系统性总结仍然具有局限性.本文不仅综述了高熵合金电催化剂的特点和设计准则,还对其应用的最新进展进行了系统性的归纳整理,对高熵合金未来的发展具有指导意义.首先我们从多个角度阐明了高熵合金作为一种优异电催化剂的原因,包括其出色的机械性能、可优化的结构和组成、大量具有高本征活性的活性位点,以及出色的稳定性.为了进一步深入对高熵合金电催化剂的理解,我们还从设计准则、元素选择,以及理论计算预测材料性质等角度,详细介绍了高熵合金的合理设计.随后,我们介绍了高熵合金电催化剂在电解水、有机小分子氧化、燃料电池和碳/氮基转化反应的最新研究进展,其中还包括了一系列理论计算和原位表征在理解催化反应机理方面的应用.最后,我们展望了高熵合金电催化剂在未来发展中面临的挑战和机遇.

摘要：高熵合金的多组分特性使其具有许多传统合金无法比拟的优异性能.然而,高熵合金传统的制备方法仍存在一定的局限性.激光选区熔化(SLM)技术可以通过逐层沉积的方式实现复杂零件的精密成形.将SLM技术与高熵合金相结合,可以充分发挥高熵合金的性能优势.本文综述了SLM制备的高熵合金的显微结构和性能特征.由于SLM工艺存在高温梯度和高冷却速率,所以在SLM制备的高熵合金中通常会形成复杂的微观结构,包括胞状亚结构、析出相、层错和纳米孪晶.此外,独特的微观结构为高熵合金带来了优异的力学性能和其他功能,表明利用SLM技术制备高熵合金具有很大的发展潜力.此外,我们还简要介绍了SLM制备的高熵合金的微观缺陷及其应用.本文为高性能高熵合金的设计提供了有益的指导.