Influence of Nozzle Expansion Ratio of Circular and Rectangular Cross-Section Nozzle on Velocity and Temperature of Copper Particle with HP Cold Spraying by Computational Fluid Dynamics and experimental analysis

In cold spray, the nozzle shape is an important factor. Among nozzle shapes, the nozzle expansion ratio, which is defined as the area of the exit divided by the area of the throat, to gas pressure is an important parameter. In this paper, the influence of the circular and the rectangular cross-section nozzle are taken into account, considering the CFD and experiments. The influence of the nozzle expansion ratio of the circular and the rectangular cross-section nozzle on the velocity and temperature of gas and particles in high-pressure cold spraying using CFD code such as ANSYS Fluent are reported. Experiments were conducted with copper particles (10μm) at pressures from 1.5 to 4 MPa. For a gas pressure of 3 MPa for copper particles, circular and rectangular cross section nozzles have a maximum particle collision velocity with an expansion ratio of about 11 to 12. The deposition efficiency of copper powder also increased.