Calculation of Velocity and Temperature of Nickel Powder Particles in a Supersonic Nozzle During Low-Pressure Cold Spraying

The article considers one of the main areas of research on cold spraying – the dynamics of two-phase flow. To obtain coatings by cold spraying, a high-speed gas flow is used to accelerate and heat the particles. The study of the general patterns of gas flow and particle movement in a given flow and gas collision with substrate is a primary task when developing recommendations for coating deposition. Since the cold spraying depends primarily on the particle velocity, it is important to understand the effect of the process parameters (pressure and temperature at the nozzle inlet), characteristics of powder particles (density, shape and size), and the nozzle geometry. The gas velocity limits the particle velocity that can be achieved in the supersonic nozzle of a cold spraying machine. The article studies the process of acceleration and heating of Nickel powder particles in the channel of the supersonic nozzle of the low-pressure cold spraying machine. The temperature-velocity parameters of the flow in the nozzle were calculated using a one-dimensional isentropic gas flow model. Based on the results of the calculations, the dependences of the effect of velocity and temperature of Nickel powder particles on the air temperature and pressure at the nozzle inlet, and charts of their acceleration and heating in the nozzle channel were developed.