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用传统铸造法制备了CoCrFeNiAl高熵合金,研究了不同退火温度对合金组织及性能的影响。结果表明,铸态的CoCrFeNiAl高熵合金为面心立方晶体结构(FCC)和体心立方晶体结构(BCC)的混合结构;随退火温度的升高,合金的晶体结构转变为FCC+BCC+Ordered BCC的混合结构;当合金温度达到800℃时,在枝晶之间开始析出AlNi_3、CrFe金属间化合物,合金的晶体结构转变为FCC+BCC+Ordered BCC+AlNi_3+CrFe的混合结构。CoCrFeNiAl高熵合金具有较高的硬度,并随着退火温度的升高,合金的硬度逐渐增大,硬度最高为463 HV0.2。CoCrFeNiAl高熵合金具有较好的室温压缩性能,铸态合金的压缩断裂强度、压缩率分别可达2275 MPa、18.8%。随着退火温度的升高,塑性逐渐降低,但强度逐渐增加,经600℃退火后,具有最佳的室温压缩性能,压缩断裂强度、压缩率分别为2631 MPa、12.5%。
The CoCrFeNiAl high entropy alloy was prepared by the traditional casting method and the effect of different annealing temperature on the microstructure and properties of the alloy was studied. The results show that the as-cast CoCrFeNiAl high entropy alloy is a mixed structure of FCC and BCC. With the increase of annealing temperature, the crystal structure of the alloy is transformed into FCC + BCC + Ordered BCC. When the alloy temperature reached 800 ℃, AlNi_3 and CrFe intermetallic compounds began to precipitate between the dendrites, and the crystal structure of the alloy was transformed into a mixed structure of FCC + BCC + Ordered BCC + AlNi_3 + CrFe. CoCrFeNiAl high-entropy alloy has a higher hardness, and with the annealing temperature increases, the hardness of the alloy gradually increased hardness up to 463 HV0.2. CoCrFeNiAl high-entropy alloys have better room-temperature compressive properties. The compressive rupture strength and compressibility of as-cast alloys can reach 2275 MPa and 18.8% respectively. With the increase of annealing temperature, the ductility decreased gradually, but the strength increased gradually. After annealing at 600 ℃, it had the best room temperature compressive properties. The compressive rupture strength and compressive strength were 2631 MPa and 12.5% respectively.