Numerical Study of Multi-particle Impacts during Cold Spray Using Peridynamic Simulations

Numerical simulations, predominantly focusing on single-particle models, have been extensively used to study particles impacting behavior in cold spraying. However, the formation and properties of the deposited layer are influenced not only by a single particle impact but also by the subsequent impacts. Furthermore, numerous existing simulation methodologies frequently neglect the consideration of interfacial adhesion, leading to particle decohesion and rebound. Therefore, we conducted numerical simulations based on the meshless and nonlocal peridynamics (PD) method, in which a three-dimensional multi-particle model incorporating varying particle sizes was developed to simulate copper particles impacting a copper substrate, with adhesive forces considered at both particle-substrate and particle-particle interfaces. The proposed model predicts coating morphology, interfacial characteristics, compression ratio, and porosity, with its validity confirmed through comparison with experimental results reported in the literature. The results show that subsequent impacts significantly influence the cohesion, adhesion, and deformation of previously deposited particles, and enhance deposition efficiency by continuous tamping. The peridynamics (PD) simulation approach provides a comprehensive and highly realistic description of the impact and bonding behaviors during the cold spray coating build-up process.