| Effect of Gun Nozzle Geometry and Powder Injection Position on Properties of Cold Sptayed Titanium and Copper Coatings | ||
| Prof. Kazuhiko Sakaki, Shuhei Shinkai, Nobuharu Ebara, Tetsuya Suenaga and Yasuo Shimizu, Department of Mechanical Systems Engineering, Faculty of Engineering, Shinshu@University, 4-17-1 Wakasato, Nagano-shi, 380-8553, Japan Nozzle geometry, which influences gas dynamics and, therefore, sprayed particle behavior is one of the most important parameters in cold spray process. The gas flows in the entrance convergent section of the nozzle exhibit a relatively higher temperature and are subsonic; thus; this region is most suitable for heating spray particle. In this study, numerical simulation and experiments investigated the effect of the nozzle contour (convrtgent –divergent and convrtgent-divergent-barrel), entarance geometry of convrtgent –divergent nozzle and powder injection position at nozzle on the cold spray process. The process changes inside the nozzle as obtained by numerical simulation studies were related to the coating properties. A titanium and copper powder was used for the experimental studies. Working gas (is nitrogen) pressure and temperature at nozzle-intake were 3MPa and 350KC. The change in the nozzle and contouentrance convergent section length of the gun nozzle had a significant effect on the deposition efficiency and microstructure. The deposition efficiency increased as this geometry increased. | ||