Numerical Study of Copper Particle Deposition Process and Residual Stress During Cold Spraying

Abstract

In order to investigate the acceleration and deformation behavior of particles during cold spraying, the finite element method was used to simulate the acceleration process of copper particles with different sizes inside the Laval spray gun, and the accuracy of the simulation results was verified through particle image velocimetry. Meanwhile, the multi-particle collision model was established using a coupled Eulerian-Lagrangian method with Python script to simulate the deposition process of copper particles and analyze the residual stresses of the copper coating. The simulation results of particle acceleration indicated that the velocity of the same material increased as the particles size decreased under the same spraying conditions. The simulated particle velocity distribution closely matched the actual velocity distribution during spraying, with only a 3.5% difference in average values. Under the conditions of 3 MPa and 723 K, the collision process of particles at different moments was simulated, and the deposited particles were compacted by subsequent particles, causing severe deformation and filling of the pores between the deposited particles, forming a dense coating. The residual stress of the coating simulated by the multi particle collision model(-57.02 MPa) was close to the measured value(-42.68 MPa), demonstrating that this model could effectively reflect the formation of the coating and the distribution of internal residual stresses.

Keywords

• cold spraying；numerical simulation；particle velocity；particle image velocimetry；residual stress