Particle deformation behavior and pores distribution of cold sprayed Ti coatings

In the deposition process of Cold Spraying (CS), the bonding strength between particles is small, and defectsas pores and interparticle boundaries are common in the coatings. In order to study the formation mechanism of these defects, three kinds of Ti coatings with different particle sizes distributions were prepared at different airflow temperatures. According to the experimental parameters, the Coupled Euler-Lagrange (CEL) model of random multi-particle deposition was established, and the deformation of particles after deposition and the pores distribution law inside the coatings were calculated. The results showed that the numerical simulation and experimental results were in good agreement. The collision action causes the accumulation of particles to be directional, and with the increase of velocities, the deformation of particles increases, and the inner particles are more affected by the velocities than the outer particles. Under the same parameters, the deposits with large particles have larger pores and higher porosities. At low velocities, the pores inside the coatings communicate with each other to form pore clusters, and as the velocities increase, the pore sizes decrease and the porosities decrease.