Numerical Simulation of a Modified Nozzle for Cold Spraying

The purpose of the paper is to study the velocity of aluminum and nickel powder particles in the channel of a modified nozzle for low-pressure cold spraying and compare it with the values obtained for a standard nozzle using the method of computational gas dynamics. The authors propose a hypothesis about the possibility of improving the properties of coatings during low-pressure cold spraying by providing higher values of the velocity of the powder particle at the moment of contact with the substrate. Based on the standard cold spray nozzle, a new geometry of the flow part of the nozzle has been developed. Simulations were performed using the computational gas dynamics method in the ANSYS FLUENT software package. Based on the simulation results, the flow velocity distribution patterns in the standard and modified nozzles were obtained, and graphs of the velocity of aluminum and nickel particles in these flows were constructed. It was found that the velocity of aluminum and nickel particles at the moment of contact with the substrate for the modified nozzle is 14.6% and 12%, respectively, higher than the velocity values for the standard nozzle under the same initial conditions. The novelty of the obtained results is that the influence of the geometry of the cold spray nozzle channel on the particle impact velocity is demonstrated. The practical value is that the obtained results can be used in developing technological recommendations for cold spraying of coatings for a modified nozzle and its further optimization.