Effects of Mn content on mechanical properties of FeCoCrNiMn_x (0 ≤ x ≤ 0.3) high-entropy alloys (HEAs) are investigated via first-principles calculations combining EMTO–CPA method. Related physical parameters, including lattice constant, elastic constants, elastic modulus, Pugh’s ratio, anisotropy factors, Poisson's ratio, Cauchy pressure, Vickers hardness, yield strength, and energy factor, are calculated as a function of Mn content. The results show that the resistances to bulk, elastic, and shear deformation decrease with increasing Mn content. Pugh’s ratio \({B \mathord{\left/ {\vphantom {B G}} \right. \kern-\nulldelimiterspace} G}\) indicates that the ductility of FeCoCrNiMn_x HEAs has a remarkable reduction between 22 and 24% of Mn content. Meanwhile, Cauchy pressure suggests that the atomic bonding transforms from metallic to directional characteristic from 22 to 24% of Mn content. Vickers hardness and yield strength of FeCoCrNiMn HEA are intrinsically larger than those of FeCoCrNi HEA. Dislocation nucleation easily occurs in FeCoCrNiMn HEA compared to FeCoCrNi HEA, and large dislocation width in FeCoCrNiMn_0.2 HEA results in low stacking-fault energy, which easily induces twinning deformation. This work provides a valuable insight for further theoretical and experimental study on the mechanical properties of FeCoCrNiMn_x (0 ≤ x ≤ 0.3) HEAs.

上FeCoCrNiMn的机械性能Mn含量的影响_X（0≤  X  ≤0.3）高熵合金（HEA与）经由第一原理计算组合EMTO-CPA法研究。计算出相关的物理参数，包括晶格常数，弹性常数，弹性模量，普格比，各向异性因子，泊松比，柯西压力，维氏硬度，屈服强度和能量因数，作为Mn含量的函数。结果表明，随着Mn含量的增加，抗膨松，弹性和剪切变形的能力降低。Pugh的比率\（{B \ mathord {\ left / {\ vphantom {BG}} \ right。\ kern- \ nulldelimiterspace} G} \）表明FeCoCrNiMn _x的延展性HEA的锰含量降低了22％至24％。同时，柯西压力表明，原子键从金属含量转变为锰含量的22％至24％的方向性特征。FeCoCrNiMn HEA的维氏硬度和屈服强度本质上大于FeCoCrNiHEA的维氏硬度和屈服强度。与FeCoCrNiMn HEA相比，FeCoCrNiMn HEA容易发生位错形核，FeCoCrNiMn _0.2 HEA的位错宽度大，导致堆垛层错能量低，容易引起孪晶形变。这项工作提供了进一步的理论和实验研究FeCoCrNiMn的机械性能的有价值的见解_X（0≤  X  ≤0.3）HEA与。