Numerical and experimental investigation on effect of impact velocity on particle deposition characteristics in cold spraying

摘要

This work aims to study the bonding features and mechanisms present in cold spray coatings of 304 stainless steel by linking experimental investigations with finite element modelling for the purpose of optimising the deposition process. Experimental investigations show that successful bonding is achieved only above a critical particle velocity, which could be measured by experimental methods. The numerical predicted results reveal that deformation features and interface mechanical property of deposited particles adequately explain the deposition characteristics for different impact conditions. The particle bonding mechanism can be attributed to the adiabatic shear instabilities that are caused by slide friction and compression force. Experimental and numerical results also illustrated that both particle flatten ratio and impact crater increased with increasing impacted velocity. On the basis of these results, an optimised spray parameter is essential for the coating application.