Effect of Mn element on shock response in CoCrFeNiMn x High Entropy Alloys

The effect of Mn element on shock response of CoCrFeNiMn x high entropy alloys (HEAs) are investigated using molecular dynamics simulations. Structural analysis shows that Mn-rich CoCrFeNiMn x HEA has a larger average atomic volume. The elastic properties of CoCrFeNiMn x HEAs under various hydrostatic pressures are studied, revealing that the elastic modulus decreases with increasing of Mn content. The shock thermodynamic parameters are quantitatively analyzed. The Mn-dependent shock Hugoniot relationship of CoCrFeNiMn x HEAs is obtained: U s = 1.25 + (5.21–0.011 x ) U p . At relatively high shock pressure, the increase in Mn content promotes the formation of clustered BCC structures and hinders the development of dislocations. In addition, more FCC structures in Mn-rich CoCrFeNiMn x HEAs transform into disordered structures during spallation. Spall strength decreases with increasing Mn content. This study can provide a reference for the design and application of CoCrFeNiMn HEAs under shock loading.