Elastic properties of Al CrMnFeCoNi (0 ≤ x ≤ 5) high-entropy alloys from ab initio theory
Elastic properties of Al CrMnFeCoNi (0 ≤ x ≤ 5) high-entropy alloys from ab initio theory
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DOI：
10.1016/j.actamat.2018.05.050
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发表时间：
2018-08
期刊：
影响因子：
9.4
通讯作者：
Hualei Zhang;Xun Sun;S. Lu;Zhihua Dong;Xiangdong Ding;Yunzhi Wang;L. Vitos
中科院分区：
文献类型：
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作者：
Hualei Zhang;Xun Sun;S. Lu;Zhihua Dong;Xiangdong Ding;Yunzhi Wang;L. Vitos
采用从头算方法研究了体心立方（bcc）和面心立方（fcc）结构的顺磁性AlxCrMnFeCoNi（0 ≤x≤ 5）高熵合金（HEAs）的弹性性质.与现有的实验数据的比较表明，所采用的方法准确地描述了弹性模量。预测的晶格常数随着Al的加入而单调增加，而弹性参数表现出复杂的组成依赖性。两个相的弹性各向异性都异常高。只有当考虑到强弹性各向异性时，用柯西压力和Pugh比表示的脆性/韧性转变才变得一致。CrMnFeCoNi的负柯西压力是由于相对较低的体积模量和C12弹性常数，这反过来又与相对较低的内聚能相一致。本研究结果结合实验数据表明HEAs系统的异常金属字符。
Usingab initiocalculations, we investigate the elastic properties of paramagnetic AlxCrMnFeCoNi (0 ≤x≤ 5) high-entropy alloys (HEAs) in both body-centered cubic (bcc) and face-centered cubic (fcc) structures. Comparison with available experimental data demonstrates that the employed approach describes accurately the elastic moduli. The predicted lattice constants increase monotonously with Al addition, whereas the elastic parameters exhibit complex composition dependences. The elastic anisotropy is unusually high for both phases. The brittle/ductile transitions formulated in terms of Cauchy pressure and Pugh ratio become consistent only when the strong elastic anisotropy is accounted for. The negative Cauchy pressure of CrMnFeCoNi is due to the relatively low bulk modulus andC12elastic constant, which in turn are consistent with the relatively low cohesive energy. The present findings in combination with the experimental data suggest anomalous metallic character for the HEAs system.