Microstructure prediction in the cold spraying process of high entropy alloys using a dislocation-based model

This study focuses on the cold spray of CoCrFeMnNi high-entropy alloy (HEA), known as Cantor alloy. To predict the relationship between the Cantor alloy’s microstructure and process factors, a detailed understanding of microstructure, particularly the ability to predict or analyze dislocation density during particle impact, remains a critical gap. The deposition of a single particle was simulated using a Lagrangian finite element framework, with a dislocation-based model employed to quantify the plastic deformation. VUMAT subroutines were integrated to model the microstructural characteristics during impact, enabling the calculation and comparison of mises and yield stresses and determining strain variables. Additionally, a scanning electron microscope (SEM) and electron backscatter Diffraction (EBSD) were used to compare the numerical predictions with experimental observations. The results demonstrated that the model effectively predicted the microstructural evolution of the impacted particles, focusing on calculating dislocation density in relation to plastic strain. The findings showed that as one moves from the top of the particle toward the interface, there is a noticeable increase in dislocation density. This increase in dislocation density can be attributed to an increase in the strain deformation near the interface, which was in agreement with FEM simulations and microstructural analysis.