S044023 Influence of cross sectional shape of cold spray nozzle on spray pattern

In the cold spray process, cross-sectional shape of the nozzle has a significant effect on spray pattern of coatings. There is a rectangular and round cross-sectional shape on the cold spray nozzle. It has been reported that spray pattern of the rectangular spray nozzle is wider than that of the round spray nozzle. Accordingly, rectangular nozzle is better efficiency than round nozzle at spray a constant width. However, cold spray nozzle on the market is mostly round nozzle. Therefore, the purpose of this study is the uniformity of the spray pattern of coatings. We made two different rectangular nozzles to compare with the round nozzle. As a result, spray pattern were fabricated by converging-diverging rectangular nozzle has become more uniform and wider than that of round nozzle. However, in the converging-diverging-barrel rectangular nozzle coating was deposit to end on spray pattern of coatings. According to the numerical simulation, N^2 gas velocity that vertical to spray and width direction is quite different comparing the converging-diverging-barrel rectangular nozzle and converging-diverging rectangular nozzle at divergent section. Converging-diverging-barrel rectangular nozzle velocity is 150m/s and Converging-diverging rectangular nozzle velocity is 30m/s. In addition, in velocity of the spray direction end portion is 50m/s larger than nozzle center in the converging-diverging-barrel rectangular nozzle barrel section.