P. H. Liao, C. Zhang, C. Coddet, University of Technology Belfort-Montbeliard, Belfort Cedex, France; W. Y. Li, Northwestern Polytechnical University,, Xi'an, China; X. GUO, UTBM, Belfort, France; L. Dembinski, LERMPS – UTBM, Belfort, France
Cold spray is an emerging coating process in recent years. It has attracted worldwide interest for the fast deposition of high-quality metallic coatings. Many investigators have examined this process by both experiment and numerical simulation on the processing parameters, microstructure and corresponding properties of the deposits. However, there are still some underlying problems to be clarified. This paper deals with the impact melting phenomenon at the interfaces of high speed metallic particles in cold spraying and its effect on coating microstructure evolution and bonding mechanism. According to the previous observation of impact fusion in cold spraying of Sn and Zn, in this study, different materials of various thermal and mechanical properties were selected as feedstock. They are Al-12Si, Al2319, Ti and Ti-6Al-4V powders. It was found that the impact fusion at the local particle interfaces was observed for all the selected materials, although they had different properties. The low melting points of Al alloys, the poor thermal conductivity and surface reactivity of Ti and its alloys are attributed to the impact melting at the local contact interfaces of the particles.
Summary: According to the previous observation of impact fusion in cold spraying of Sn and Zn, in this study, different materials of various thermal and mechanical properties were selected as feedstock. They are Al-12Si, Al2319, Ti and Ti-6Al-4V powders.
