采用水冷铜坩埚真空感应悬浮熔炼工艺制备AlCoCrFe1.5Ni高熵合金,然后分别在800,900,1 000℃下对其进行退火热处理,研究了退火前后合金的显微组织、硬度和耐蚀性能。结果表明:退火前AlCoCrFe1.5Ni高熵合金为BCC结构,组织为典型的等轴晶;在800℃退火后,合金中有FCC相和σ相析出;在1 000℃退火后,析出相为BCC相和FCC相,无σ相;在低于900℃的温度下退火后,合金具有较好的抗高温软化性能,在1 000℃退火后硬度下降明显,由退火前的510HV降至400HV;退火前后合金的耐蚀性能均优于304不锈钢的,随着退火温度升高,合金的耐蚀性能逐渐增强;在1 000℃退火后,合金的耐蚀性能优于904不锈钢的。
A high entropy alloy was prepared by water cooled copper crucible vacuum induction levitation melting, and then annealing heat treatment of the alloy was carried out at 800 ℃, 900 ℃ and 1 000 ℃; Microstructure, hardness and corrosion resistance of the alloy before and after annealing were studied. The results show that, before annealing, the alloy was composed of a single BCC structure and its microstructure was made up of typical equiaxed grain. There were FCC and a phases precipitated after annealing at 800 ℃. After annealing at 1 000 ℃, the precipitates were BCC and FCC phases, and there was no σ phase. The resistance to high temperature softening of the alloy was good after annealing below 900 ℃, the hardness of the alloy decreased obviously from 518 HV to 400 HV after annealing at 1 000 ℃. The corrosion resistance of the alloy before and after annealing was better than that of 304 stainless steel. With the increase of annealing temperature, the corrosion resistance of the alloy increased gradually. After annealing at 1 000 ℃, the corrosion resistance of the alloy was better than that of 904 stainless steel.