ABSTRACT

To improve the strength of single FCC phase Al_0.6CrFe₂Ni₂ high entropy alloy without reducing the plasticity, nano-phase SiC was selected as reinforcement phase. Aseries of as-cast SiC/Al_0.6CrFe₂Ni₂ high entropy alloys with different SiC content (0, 1.25, 2.5, 3.75, 5 vol%) were prepared by vacuum arc melting furnace. And the effect of SiC addition on the microstructures and mechanical properties of Al_0.6CrFe₂Ni₂ high entropy alloy was analysed by microstructure observation, element distribution analysis, compression tests and hardness tests. The results show that the Cr₇C₃ particles were found in the grain boundaries due to the decomposition of SiC in high temperature, the size and quantity of Cr₇C₃ particles grow and spread throughout the alloy gradually with the further increase of SiC content. When the added SiC content is 2.5 vol%, the alloy has better comprehensive properties, the yield strength and hardness are 618.43 MPa and 250.78 HV, respectively.

摘要

为了在不降低塑性的情况下提高单相FCC Al _0.6 CrFe ₂ Ni ₂ 高熵合金的强度，选用纳米相SiC作为增强相。 采用真空电弧熔炼炉制备了一系列不同SiC含量（0、1.25、2.5、3.75、5vol%）的铸态SiC/Al _0.6 CrFe ₂ Ni _{2高熵合金。} 并通过显微组织观察、元素分布分析、压缩试验和硬度试验分析了添加SiC对Al _0.6 CrFe ₂ Ni _{2高熵合金组织和力学性能的影响。}结果表明，Cr ₇ C 由于SiC在高温下分解，在晶界发现了3个颗粒，随着SiC含量的进一步增加，Cr 7 C 3 颗粒的尺寸和数量_逐渐 在合金中生长_和扩散_。当SiC添加量为2.5 vol%时，合金具有较好的综合性能，屈服强度和硬度分别为618.43 MPa和250.78 HV。