Aluminum powder of 99.85 wt.% purity has been sprayed onto three kinds of glass substrates by cold spray. An interface between Aluminum coating and all glass substrates were smooth, and the single aluminum particle adhered without a gap. It is not observed erosion damage of glass substrate by aluminum with lower impact velocity than critical velocity. In Aluminum coating and the neighborhood of interface of Soda-lime glass substrate, sodium included in glass substrate was distributed in high density. There might be the stratum that the element which constituted an aluminum coating and glass substrate scattered, and it was suggested that the solid-phase joining by a chemical reaction were initiated.

Nozzle geometry influences gas dynamics, such as gas density, velocity and temperature, making sprayed particle behavior one of the most important parameters in cold spray process. Gas flow at the entrance convergent section of the nozzle takes place at relatively high temperature and are subsonic. Thus, this region is a very suitable environment for heating spray particle. In this study, numerical simulation and experiments were conducted to investigate the effect of nozzle contour (convergent –divergent and convergent-divergent-barrel), entrance geometry of convergent–divergent nozzle and powder injection position at nozzle on the cold spray process. The process changes inside the nozzle were observed through numerical simulation studies and the results were used to find a correlation with coating properties. A copper and titanium powder was used in the experiments. Working gas (is nitrogen) pressure and temperature at nozzle-intake were 3MPa and 623K, respectively. In addition, the change in the nozzle contour and the change in the entrance convergent section length of the gun nozzle were found to have a slight effect on the coating microstructure. Powder injection position was also found to influence deposition efficiency and coating properties. Deposition efficiency of both copper and titanium increase with increasing the length of the convergent section of the nozzle.