High Entropy Alloys (HEAs) are promising for next-generation structural materials due to their potential to enhance their mechanical properties by optimizing their underlined microstructure via compositional variations and processing design. Establishing the relationship between the properties and underlined microstructure is, thus, a stepping stone for developing such materials for modern engineering applications. In this work, we aim to establish the relationship between the distribution of grain size representing the polycrystal microstructure and the inelastic behavior of HEAs. Our approach is a mesoscale formulation wherein we model the inelastic deformation using a distribution of the nucleation sites for local inelastic deformation, nucleated discretely over the space as loading increases. We consider the grain size distribution, experimentally or computationally generated, as our input for generating the distribution of the nucleation sites and their corresponding nucleation strengths, and we use the Von Mises stress criterion for nucleation. Each grain contains several nucleation sites that will nucleate with loading. Once a nucleation site gets nucleated, we put a certain amount of eigenstrain and use the analytical Eshelby inclusion solution to computer the disturbance in the mechanical field and image field that enforces the prescribed boundary conditions of the boundary value problem. The image field boundary value problem is solved by the finite element method using ABAQUS software. We will discuss the yielding and hardening of the stress-strain response of several HEAs with different microstructures by considering the distributions of nucleation sites and biases in the nucleation pattern.
2025-04-09 09:00:00
