Abstract

A refractory ReTaWNbMo high-entropy alloy (HEA) with an equal atomic ratio prepared by rapid solidification displays a BCC crystal structure. After annealing the as-quenched samples at 673, 873, 1073, and 1273 K for 12 h, respectively, the crystalline phase still keeps its BCC structure, but the crystalline morphology transforms from coarse dendrites to fine equiaxed crystals together with gradual grain refinement. The intragranular regions are enriched in W and Ta, while the crystals in the intergranular regions are enriched in Nb, Mo, and Re. With the increase in annealing temperature, the yield strength increases, and the compressive plasticity and fracture strength are obviously enhanced. The failure mode gradually changes from transgranular to intergranular fracture. Furthermore, the corrosion behaviors of the as-cast ReTaWNbMo HEA and the annealed states in a 3.5 wt.% NaCl solution were also studied. The samples annealed at 1273 K exhibit the best corrosion resistance due to the elemental re-distributions within grains.

中文翻译：

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难熔高熵ReTaWNbMo合金的组织，力学性能和腐蚀行为

抽象的

通过快速凝固制备的具有相等原子比的难熔ReTaWNbMo高熵合金（HEA）显示出BCC晶体结构。将淬火后的样品分别在673、873、1073和1273 K下退火12 h后，晶相仍保持其BCC结构，但晶体形态从粗枝晶转变为细等轴晶，并逐渐进行晶粒细化。晶内区域富含W和Ta，而晶间区域晶体富含Nb，Mo和Re。随着退火温度的升高，屈服强度增加，抗压塑性和断裂强度明显提高。破坏模式从沿晶向逐渐断裂转变为沿晶断裂。此外，还研究了铸态的ReTaWNbMo HEA在3.5 wt％NaCl溶液中的腐蚀行为和退火态。由于晶粒内元素的重新分布，在1273 K下退火的样品表现出最佳的耐腐蚀性。