Cold spray for ceramic metallisation: a review

Abstract

Since invented in 1980s, cold spraying (CS) has received numerous attentions recently because of its low heat input and high efficiency. Severe plastic deformation induced by high-velocity impaction makes the particles with temperature below the melting point deposited on the substrate. Theoretically, the coating obtained by CS is dense and free of oxidation, so excellent thermal and electrical conductivity can be obtained, which is ideal for ceramic metallisation (CM). Many studies have been done on the CS CM to study the coating structures, bonding mechanism and performances. Mechanical occlusion is considered to be the main bonding type at the interface, local melting plays a small role in the bonding, but local melting improves the bonding strength significantly. However, the specific bonding mechanism of CS CM is still unclear, especially in some metal/ceramic systems with bonding strength greater than 10 MPa, the bonding mechanisms need to be further studied. CS is also difficult to metallise some ceramics, which requires complicated design. Thus, aiming to improve the reliability and the extent of the application of CS CM, a thorough review should be made. In the present paper, the bonding mechanisms of CS metal coating on ceramic proposed by previous researches were summarised to help the researchers a better and quicker understanding for the CS CM. The factors influencing the properties were introduced. The author also made an outlook for the future development of CS in CM.