Microstructure, Thermal and Electrical Properties of Aluminum Coatings Produced by Cold Spraying
Yoshiyasu ITOH and Shoko SUYAMA
Abstract:A cold spray process has been developed for dense and clean and tightly bonded coatings in contract with other established thermal spray processes. The cold sprayed aluminum is particularly well suited for metallic coatings, such as electric conductor and corrosion resistance. However, the thermal and electrical properties of aluminum coatings formed by the cold spray have not always been clarified. Two kinds of free-standing aluminum specimens, which were formed by the cold spray process and an atmospheric plasma spray process, were machined from the thick coatings and were used for measuring the thermal conductivity, specific heat and electrical resistivity etc. The experimental results suggested that the porosity and oxide content had important effects on the thermal and electrical properties. Namely, high thermal conductivity and the low electrical resistivity of coatings could be obtainedfrom the cold spray process, because of the low porosity and the low oxide content. Key Words:Microstructure, Density, Thermal conductivity, Specific heat, Electric resistivity, Aluminum coating, Cold spraying, Atmospheric plasma spray