Effect of Thickness on the Residual Stress Profile of an Aluminum Cold Spray Coating by Finite Element Analysis

Abstract

This research investigates the influence of thickness on residual stress profiles in aluminum cold spray coatings using finite element analysis (FEA). Residual stress is a critical factor that impacts coating adhesion, fatigue life, and susceptibility to delamination in thermal spray processes. Despite its acknowledged importance, predictive analysis of these stresses on a layer-by-layer basis remains relatively unexplored. This study introduces an innovative numerical methodology to analyze the progression of residual stresses across various deposition efficiencies (10%, 40%, 60%, and 100%) and layer thicknesses, thereby enhancing predictive accuracy for cold spray coatings. The findings demonstrate that the number of deposited layers significantly affects residual stress profiles in both coatings and the substrate, with compressive residual stress predominating in the coatings and deeper tensile stress predominating in the substrate. Residual stress behavior near the last deposited layer aligns with the expected peening effect. Discrepancies in substrate stress distributions may arise from variations in deposition parameters and unconsidered temperature effects. While the model generally aligns with theoretical and some empirical data, observed discrepancies underscore the need for further validation. This study lays the groundwork for informed decision-making for cold spray processes by providing insights into stress management, thereby contributing to enhancing coating integrity and performance.