Deposition characteristics of cold sprayed Inconel 718 particles on Inconel 718 substrates with different surface conditions

This article examined the coating/substrate interface characteristics of IN718 coatings deposited on IN718 substrates using a high pressure cold spray technique. The study was aimed at a greater insight into the coating/substrate bonding mechanism under varying substrate conditions, namely surface roughness and surface preheating, from both experimental data and simulations. The coating/substrate interface microstructure and bonding strength were systematically investigated. The coating/substrate strengths were measured by using tensile and shear tests. A finite-element model on the single particle impact was used to explain and validate the experimental data and analyze the particle bonding behavior with the substrate at different preheating temperatures. The analysis of the coating/substrate interface revealed that a polished IN718 substrate surface could promote adiabatic shear instability as well as the formation of material jetting and thus resulting in a high interface bonding strength. In addition, the preheating of the substrates could increase the metallurgical bonding and promote the coating/substrate adhesion strength.