Al 0.1 CoCrFeNi高熵合金的力学性能和变形机理
摘要
The Al<sub>0.1</sub>CoCrFeNi high-entropy alloy (HEA) was melted by vacuum magnetic levitation, and quasi-static tensile experiments were performed by using an INSTRON mechanical testing system. The crystal structure, surface morphology, composition, microstructure, hardness, and creep behavior of the samples before and after the experiment were analyzed by X-ray diffraction, optical microscopy, scanning electron microscopy, transmission electron microscopy, and nanoidentation. Results reveal that after tensile deformation, the alloy has an excellent strength-ductility combination, a significant strain-hardening effect, and an improved creep resistance. The fracture mode of sample is the typical microvoid accumulation fracture; there are a lot of microbands (the band width is about 200-300nm) inside the grains. The excellent strain-hardening ability is believed to be originated from the microband-induced plasticity effect during tensile loading.