Температурна залежність границі плинності в термінах двох компонент поля зсувних напружень в площині ковзання в сплаві CrCoNiFeMn

Abstract

The temperature dependence of the yield strength in the multicomponent CrCoNiFeMn alloy was investigated, using computer modelling and taking into account the short-wave and long-wave components of the shear stress field in the glide plane. The yield strength of a multicomponent alloy in the form of a concentrated solid solution without taking into account grain boundary strengthening is determined by three factors: the periodic lattice potential, the short-wave and long-wave components of the field of stochastic shear stresses in the glide plane, which are created by dissolved atoms. The force barriers resulting from the short-wave component will dominate. Overcoming them by dislocation with the assistance of applied stress and thermal activation will be a critical event to start dislocation movement. Barriers resulting from the periodic lattice potential and the long-wave component will be insignificant against the background of the short-wave component. Their effect on the yield strength can be taken into account by terms that do not depend on temperature. Thermal activation analysis of overcoming barriers resulting from a short-wave component, taking into account the probability of direct and reverse jumps through the barrier, gives the opportunity to describe the temperature dependence of the yield strength of a multicomponent alloy in a wide range of temperatures, including in the region of the high-temperature “plateau”. The dependence of the yield strength calculated in this way for the CrCoNiFeMn alloy correlates well with the corresponding experimental data. Keywords: temperature dependence, multicomponent alloy, glide plane, dislocation.