Effect of Spray Angle on Temperature Distribution within a Metallic Substrate in Cold Spraying

This study investigates the effect of spray angles on temperature within the metallic substrate in cold spraying. Computational fluid dynamic (CFD) approach is employed in the present work to achieve this objective. The simulated results show that spray angle significantly influences the gas flow regime and thus temperature distribution within the substrate. For the perpendicular spraying, the temperature gradient contours present regularly annular shape, which means the temperature only depends on the radial position. Also, the peak value is not at the geometric center but at the position slight away from the center, which results from the transition of the flow from laminar to turbulent state. Besides, in the decreasing process, there exists a secondary peak arising from the expansion waves in the adherence jet. With decreasing the spray angle, the secondary peak in the downhill direction disappears. But in the uphill direction, the expansion waves induced secondary peak still exits and the distance from the geometric center increases with the decrease in spray angle.