Observation of an Indirect Deposition Effect while Cold Spraying Sn-Al Mixed Powders onto Carbon Fiber Reinforced Polymers

摘要

Single-component tin coatings have successfully been cold sprayed onto carbon fiber reinforced polymers in previous studies at McGill University. Coatings with mixed metal powders were also sprayed to improve the deposition efficiency and coating conductivity. The results indicated a noticeable improvement in deposition efficiency related to the addition of a secondary metallic powder (aluminum, copper and zinc); this study is focused on the effect of aluminum. Following cold spray of various Sn/Al mixtures over a wide range of gas pressures, unusual coating morphologies were observed. The study of these morphologies leads to the description of two distinct deposition phases depending on the spray pressure: a direct deposition effect and an indirect deposition effect. The presence of submicron particles also supports the occurrence of a powder melting phenomenon during the process. Numerical simulations were conducted to support the description of these phenomena.