Sensitivity Analysis of Process Parameters of Warm Spraying Process Based on Response Surface Method

Warm spraying technology is a new type of low-temperature coating preparation technology based on the high-velocity oxygen fuel (HVOF) thermal spraying technology, which is often used to prepare titanium coatings. Titanium is widely used in aerospace, new energy, light industry and medicine due to its excellent corrosion resistance. In this paper, computational fluid dynamics (CFD) is used to study the in-flight behavior of titanium particles during warm spraying. A one-step chemical model and an eddy dissipation model are used to simulate the propylene combustion reaction. The flight behavior of titanium particles in the flow field is tracked by the Lagrangian method. The impact of the barrel diameter on the flow field is analyzed emphatically. When the barrel diameter is 8 mm, the Mach cone is significantly affected by the shock wave at the barrel exit. On this basis, the Box–Behnken Design (BBD) method is used to design the response surface model (RSM). The response surface equation and Monte Carlo sampling are combined to calculate the sensitivity of different process parameters to the particle deposition temperature and velocity, which lays an essential theoretical foundation for optimizing process parameters and obtaining high-quality coating.