Adhesion strength prediction of cold spray particle via smoothed particle hydrodynamics

Adhesion strength is a key indicator determining the integrity and service performance of cold spray coatings. However, traditional evaluation methods (such as pull-off tests) are not only constrained by adhesive strength but also involve time-consuming and costly processes. Consequently, developing reliable numerical prediction methods hold significant scientific and engineering value. This paper establishes a Smoothed Particle Hydrodynamics (SPH) model integrated with a physical interface interaction model to predict the adhesion strength of cold spray particles. The model simulates the formation of metal-to-metal connections between particle and substrate and utilizes the stable attractive forces generated post-bonding to enable direct numerical prediction of adhesion strength. The results indicate that adhesion strength increases nonlinearly with impact velocity, with the rate of increase gradually slowing, which is closely linked to jetting and inward curling behavior at the particle periphery. The predictions show good agreement with experimental data, validating the model's effectiveness. Furthermore, applying this method to deposition processes under various process parameters (spray angle, particle size, and initial temperature) systematically reveals quantitative relationships between these parameters and adhesion strength, demonstrating the model's potential for optimizing process windows and tailoring performance. Overall, this study provides a physics-based numerical tool for understanding and enhancing the bonding performance of cold spray coatings.