Thermo-Mechanical Deformation History and the Residual Stress Distribution in Cold Spray

Abstract

In cold spray, high gas temperatures and high velocity impact of particles introduce complex thermal and stress histories in the coating layers and the substrate. It is crucial to understand the interplay between temperature evolution and residual stress development as the residual stresses could potentially cause distortion and/or delamination. In this study, a system-level cold-spray deposition model is developed. The model includes a moving heat source, material addition and thermo-mechanical stress analyses. The heat source model is first validated by qualitatively comparing the thermal history with experimental measurements from literature. The system-level model is then used to calculate the residual stresses and distortion in the cold-sprayed Cu/steel system. The influence of the spray path on the residual stress development is systematically analyzed. The corresponding interface residual stress states are also examined for the different spray paths. Simulation results indicate that the thermo-mechanical analysis using the developed system-level model can provide an effective way to assist in optimizing the cold-spray coating deposition strategy and improve the coating performance.