Investigation of dynamic contact between cold spray particles and substrate based on 2D SPH method

Abstract

In cold spray, the study of the dynamic contact between the particle and the substrate in the high-velocity impact is essential during particle deposition. To entirely reveals the dynamic contact process, the SPH (Smoothed Particle Hydrodynamics) method is applied to virtual experiments to avoid the time-consuming and high costs in real experiments due to scale. In particular, an interface force model is proposed to completely describe the dynamic contact between the cold spray particles (CS particles) and substrate, which has the ability to eliminate the unphysical SPH particle penetration, rebounding phenomenon, and insufficient momentum transfer. The variation of the steady mean temperature of the CS particle surface with the initial velocity is analyzed and the critical velocity of particle deposition is successfully predicted. Furthermore, the effect of particle shapes on the deposition is discussed, which shows that the circular particles are more favourable to be deposited than the elliptical ones. The cold spray SPH model with the novel dynamic contact developed in this paper is in favor of understanding the mechanism of CS particles deposition and guiding the cold spray processes in a certain extent.