硼含量对 FeCoNiCrAl$_{\bf 0.1}$B$_{ x}$ 高熵合金组织和力学性能的作用

研究了硼含量对 FeCoNiCrAl$_{0.1}$B$_{x}$ ($x = 0 \sim 0.1$) 高熵合金微观组织和力学性能的作用. 结果表明: 当硼含量 $x \le 0.03$ 时, FeCoNiCrAl$_{0.1}$B$_{x}$ 高熵合金由单一面心立方(face-centered cubic, FCC)结构的 $\gamma $ 相组成; 而当硼含量 $x \ge 0.05$ 时, FeCoNiCrAl$_{0.1}$B$_{x}$ 高熵合金由 $\gamma $ 相、微量的有序态 FCC 相和硼化物组成. 硼元素的加入, 细化了 FeCoNiCrAl$_{0.1}$B$_{x}$ 高熵合金的晶粒, 提高了合金的抗拉强度, 但也降低了合金的延伸率. 在真空中拉伸时, FeCoNiCrAl$_{0.1}$B$_{x}$ 高熵合金的断口形貌均为韧窝状塑性断口.

Effects of boron content on microstructure and mechanical properties of FeCoNiCrAl$_{\bf 0.1}$B$_{ x }$ high-entropy alloy

The effects of boron content on the microstructure and mechanical properties of FeCoNiCrAl$_{0.1}$B$_{x }(x = 0{\sim}$0.1) high-entropy alloy were investigated in this study. The results suggested that the FeCoNiCrAl$_{0.1}$B$_{x}$ high-entropy alloy consisted of single face-centered cubic (FCC) $\gamma $ phases when $x\le 0.03$, whereas it consisted of FCC $\gamma $ phase, trace of ordered FCC phase, and boride when $x\ge 0.05$. With the addition of boron atoms in the alloy, the grain size of the alloy refined, tensile strength of the alloy increased, and elongation of the alloy decreased with an increase in the boron content. The fractographs of the FeCoNiCrAl$_{0.1}$B$_{x}$ high-entropy alloy exhibited all transgranular fracture patterns during tensile testing in vacuum.