Concentration Dependence of Constituent Elements on Grain Boundary Migration in High-Entropy Alloys

Abstract

High-entropy alloys (HEAs) are multicomponent alloys composed of five or more than five elements with near equimolar concentrations. In this study, molecular dynamics (MD) simulations of grain boundary (GB) migration in HEAs were performed in order to systematically investigate the concentration dependence of the constituent elements on its migration behavior. We found that the driving force required for GB migration in the model HEAs reaches the maximum when the GB migration becomes intermittent or the velocity reduces. The maximum driving force is achieved at the maximum degree of GB segregation, showing that GB segregation, which can be controlled by the element composition in the HEAs, strongly affects the GB migration behavior such as the required force for the migration and the velocity. Our study indicates that the element composition in HEAs plays an important role in determining the GB migration behavior and the obtained results contribute to designing the HEAs with superior mechanical properties.