Insights into the coupled effects of powder size and surface oxide film on deposition, microstructure and performance of cold spray additive manufactured Ti

Cold spray additive manufacturing (CSAM) offers a solid-state method for producing high-performance Ti components, yet the interplay among powder size, surface oxidation, and process parameters on deposits' microstructures and properties remains insufficiently understood. This work systematically investigates how the above factors influence powder deposition efficiency, microstructure, mechanical performance, and electrical conductivity of related Ti deposits. As a result, fine powder produces denser deposits with enhanced tensile strength, hardness, and conductivity, while coarse powder achieves higher deposition efficiency. The surface oxide films reduce inter-particle bonding, leading to more rebound particles, then increasing the hardness of Ti deposits. Increasing gas temperature increases particle kinetic energy, thus promoting oxide films fracture and mitigating the negative impact of oxidation. The study reveals the synergistic effects of powder characteristics and process conditions, providing mechanistic insights into microstructural evolution and property control. These findings offer practical suggestions for optimizing powder selection and processing strategies, enabling efficient utilization of partially oxidized powders and advancing the reliable production of high-performance titanium components via CSAM.