Metallization of Polymers by Cold Spraying with Low Melting Point Powders

Polymers and polymer composites have been increasingly used due to their low density and high specific strength; however, their low electrical conductivity has limited their further application. Cold spray has been proven to be a feasible approach to metallizing polymers. Previous results at McGill University have shown that tin coatings can be successfully cold sprayed onto polymeric substrates when spraying with a low-pressure cold spray system at gas temperatures close to the melting point of tin. The successful deposition of tin was attributed to the incipient melting of tin. In this work, three low melting point powders, including Sn, Sn-Zn alloy, and Sn-Bi alloy, are cold sprayed onto polymeric substrates. Different combinations of gas temperature and gas pressure are assessed. Based on the results, the effect of melting points of the feedstock powders on their cold sprayability on polymeric substrates is discussed.