Morphology prediction of cold-sprayed Cu and Al coatings through multi-particles deposition simulation

A deposition model of 15 particles onto a substrate was established using the finite element program ANSYS/LS-DYNA. Based on the multi-particle deposition model, the deposition behavior and morphology as well as the interface characteristic were predicted for different particles/substrate cases. Al and Cu coatings were prepared by cold spraying. The cross section of the coatings and the characters of particle deformation were observed by scanning electron microscopy and compared with the simulated results by the multiparticle deposition model. The results demonstrate that the multi-particle deposition model can predict the effect of process conditions on the deposition behavior, microscopic characteristic, and interface morphology for different particles/substrate cases. When the impact velocity is low, particle deformation is not sufficient, which easily results in holes at the junction of particles; however, the holes disappear gradually with increasing impact velocity. Compared with particles, for a hard substrate, the coatings/substrate interface is smooth, which weakens the interlock; while for a soft substrate, the substrate deforms severely to form jet-like metal, which squeezes into particles to increase the bonding.