Key Factors Affecting Cold Spray Particle Deposition: A Review of Powder Surface Oxidation

Cold spraying (CS), recognized for its solid-state deposition characteristics, holds significant potential for the fabrication of high-performance coatings, the repair of damaged components, and the additive manufacturing of metals and metal matrix composites. However, oxide films present on the surfaces of powder particles exert a profound impact on particle deformation during CS, as well as on the interfacial microstructure, bonding quality, and mechanical properties of the resulting coatings or deposits. The presence of oxide films increases the critical deposition velocity, reduces the plastic deformation capacity of particles, and promotes the formation of unbonded regions or brittle inclusions at interfaces, thereby compromising deposition efficiency and mechanical integrity. Nevertheless, under specific conditions, the oxide film on the powder surface can be fractured by particle collisions, and the resulting discontinuous oxide film may become evenly distributed, potentially contributing to the dispersion strengthening and enhancing the hardness of the coating. This study presents a comprehensive review of the deformation behavior of oxide films during the CS process and their influence on coating microstructure and properties, with particular focus on the mechanism where how oxide film influences interfacial bonding, coating microstructure and performance. Furthermore, the study discusses the importance of minimizing oxygen content in feedstock powders to achieve high-strength and high-ductility deposits, providing theoretical guidance for optimizing coating performance. Finally, the role of oxide films in CS-based additive manufacturing is explored, and prospective research directions are outlined.