Dependence of lattice distortion on temperature in CrCoNiFeMn alloy

The dependence of the average lattice distortion on temperature in the multicomponent alloy CrCoNiFeMn was investigated by computer simulation. The features of this dependence are related to the temperature dependences of interatomic distances and elastic moduli. These dependences are resulted from the anharmonicity of the interaction between atoms, i.e. the asymmetry of the interatomic potential function relative to its minimum. There are such dependences of interatomic distances and elastic moduli for the atoms of the components inside the alloy CrCoNiFeMn on temperature, each of which lies between the corresponding dependencies for the pure component and the alloy and is similar to them, while corresponding atomic size misfit and elastic modulus misfit result in lattice distortion which increases with temperature and can compensate for shear modulus decrease. Thus, it can explain the compensation of shear modulus decrease with increasing temperature, which is actually observed in experiments, where there is a “plateau” of the temperature dependence of the yield strength. This confirms the hypothesis that such compensation can depend only on the atom displacement as a result of thermal vibrations, which leads to a shift in the equilibrium position of atoms and thermal expansion of the material when the temperature rises. Keywords: lattice distorsion, solid solution, temperature, multicomponent alloy.