Potential of cold spray as additive manufacturing for TI6AL4V

Cold spray can be regarded as a high build-speed (300-400 cm³/h) additive manufacturing technology that is capable of non-thermal freeform fabrication on any surface profile. It uses a high pressured and preheated gas stream to accelerate the microparticles via a converging-diverging nozzle to supersonic speeds and impact onto the substrate. The micro-particles will then plastically deform and bond with the substrate. Cold spraying of Ti6Al4V (or Ti64) would be beneficial for many industries because of the build speed and minimal material wastage. However, recent studies showed that cold spraying of Ti64 coating is challenging due to the coating's poor interfacial bonding to the substrate surface, limited coating thickness and relatively high porosity level from 5 to 20%. In this work, we have successfully deposited high-quality cold sprayed Ti64 coatings on Ti64 substrates. The microstructure and mechanical properties of the Ti6Al4V coatings were systematically investigated.