CoCrFeNiTiAlx高熵合金的组织演变及其力学性能研究

Study on Microstructure Evolution and Mechanical Properties of CoCrFeNiTiAl_x High Entropy Alloys

采用真空电弧炉熔炼法制备了CoCrFeNiTiAl_x高熵合金(x=0、0.25、0.5、0.75、1、1.5、2,x为摩尔比)。研究了Al含量对于CoCrFeNiTiAl_x高熵合金相结构和力学性能的影响。结果表明:CoCrFeNiTi合金为FCC晶体结构。随着Al含量的增加,晶体结构开始向BCC晶体结构转变。CoCrFeNiTiAl_x合金的显微组织为树枝晶组织,枝晶区富含Co、Ni、Ti和Al元素,枝晶间富含Cr和Fe元素。CoCrFeNiTiAl_x展现出优异的室温力学性能,当x=0.5时性能最佳,枝晶区显微硬度为829HV、枝晶间显微硬度为952HV、抗压强度为2.023GPa、弹性模量为21.29GPa。

CoCrFeNiTiAlx high entropy alloys(x=0,0.25,0.5,0.75,1,1.5,2,x is the mole ratio)were prepared by vacuum arc melting.The effects of Al content on the phase structure and mechanical properties of CoCrFeNiTiAlx high entropy alloys were studied.The results show that Co Cr FeNiTi alloy exhibits FCC crystal structure.With the increase of Al content,the crystal structure transfers to BCC crystal structure.The microstructure of CoCrFeNiTiAlx alloy is dendritic structure.The dendritic region is rich in Co,Ni,Ti and Al,and the interdendritic region is rich in Cr and Fe.CoCrFeNiTiAlx shows excellent mechanical properties at room temperature,when x=0.5,the properties of the aloy are the best one,then,the microhardness of the dendritic region reaches 829 HV,the interdendritic microhardness is 952 HV,the compressive strength is 2.023 GPa,and the elastic modulus is 21.29 GPa.