The elastic constants, ideal tensile strength (ITS), stacking fault energy (SFE), lattice constant and magnetic moment of FeMnCoCrNi high entropy alloys with varying Co and Cr contents at 0 and 300 K were systematically investigated by first-principle calculations. For the alloys with Co substitution for Ni, at both temperatures the elastic stability of the face-centered cubic (fcc) phase, bulk elastic modulus (B), Young's modulus (E), shear modulus (G) and ITS increase monotonically with increasing Co content. However, the Cauchy pressure (C_P), Pugh ratio (B/G), Poisson ratio (v), Zener anisotropy ratio (A_Z) and elastic anisotropy ratio (A_VR) decrease monotonically. The SFE also decreases with the increase of Co, resulting in the change of plastic deformation mechanism from dislocation slip to mechanical twinning, and then to hcp-martensitic transformation. This elucidates the underlying mechanism of the effect of Co addition on the strength and micromechanical behavior of FeMnCoCrNi alloys. Compared with Co, the Cr substitution for Ni leads to the more complex change of elastic constants and ITS. The increase of Cr shows the similar effect on SFE and deformation mechanism as that of Co. The variation of valence electron concentration and magnetism affect the SFE. The increase of either Co or Cr leads to the reduced magnetic moments of Fe and Mn. This could be responsible for the monotonic decrease of both lattice constant and SFE as the Co content increases. However, for the Cr addition case, multiple factors may affect the evolution of lattice constant and SFE. These findings shed light on the deformation mechanism of the alloys with different compositions.

通过第一性原理系统地研究了Co和Cr含量在0和300 K下变化的FeMnCoCrNi高熵合金的弹性常数，理想抗拉强度（ITS），堆垛层错能（SFE），晶格常数和磁矩。对于用Co代替Ni的合金，在两个温度下，面心立方（fcc）相的弹性稳定性，体弹性模量（B），杨氏模量（E），剪切模量（G）和ITS均随着增加而单调增加。钴含量。但是，柯西压力（C _P），Pugh比（B / G），泊松比（v），齐纳各向异性比（A _Z）和弹性各向异性比（A _VR）单调减少。SFE也随着Co的增加而降低，导致塑性变形机制从位错滑移到机械孪晶再到hcp-马氏体转变。这阐明了添加Co对FeMnCoCrNi合金的强度和微机械性能的潜在机理。与Co相比，Cr替代Ni导致弹性常数和ITS的变化更为复杂。Cr的增加对SFE和变形机理的影响与Co相似。价电子浓度和磁性的变化会影响SFE。Co或Cr的增加导致Fe和Mn的磁矩减小。随着Co含量的增加，这可能是晶格常数和SFE单调降低的原因。然而，对于添加Cr的情况，多个因素可能会影响晶格常数和SFE的演化。这些发现揭示了具有不同组成的合金的变形机理。