Studies of splat morphology and rapid solidification during thermal spraying

The splat morphology and substrate melting and re-solidification have been studied numerically and experimentally for molybdenum droplets impacting on molybdenum, mild steel, and glass substrates. The effects of the droplet size, velocity, temperature, and substrate material and temperature on the splat morphology and the rate of solidification have been investigated. The correlation between the splat flattening ratio and the Reynolds and Jakob numbers has been developed. The substrate melting and re-solidification strongly depends on the impinging temperature of the droplet, substrate temperature and its thermophysical properties. A two-dimensional model considering free surface deformation and rapid solidification has been developed and used to predict the splat morphology.