热处理对AlFeCrCoNiMo高熵合金微观组织与硬度的影响

利用真空电弧熔炼法制备了AlFeCrCoNiMo高熵合金。用X射线衍射(XRD)、扫描电镜(SEM)、硬度仪,研究了退火对高熵合金的微观组织及硬度的影响。结果表明:铸态以及退火后的合金是树枝晶结构,枝晶间是由Cr_9Mo_(21)Ni_(20)和NiCoCr金属间化合物组成的共晶结构;随着退火温度的升高,FCC相逐渐减少,并会析出新的金属间化合物;合金的微观应力表现出先增大后减少的变化趋势;合金的硬度随着退火温度的升高先升高再降低,合金的应力与硬度的变化趋势一致,当退火温度达到800℃时,合金的硬度达到最大。

Influence of heat treatment on microstructure and hardness of high entropy alloy AlFeCrCoNiMo

High entropy alloy AlFeCrCoNiMo was prepared by vacuum arc melting, and the influences of annealing on the microstructure and hardness of high entropy alloys were investigated by X.ray diffraction (XRD), scanning electron microscopy(SEM) and hardness tester.The results show that the crystal structure of cast alloy and annealed alloy is dendritic structure, which is composed of Cr9Mo21Ni20 and NiCoCr intermetallic compound eutectic structure.The FCC phase decreases gradually and will release new intermetallic compound with the rising of annealing temperature.The microscopic stress of alloy shows a variation trend of increasing first and then decreasing, and its hardness increases first and then decreases with the rising of annealing temperature.The variation trend of stress and hardness of alloy is consistent.The maximum hardness is obtained when the annealing temperature reaches 800 ℃.