Numerical simulation and parameter sensitivity analysis of multi-particle deposition behavior in HVAF spraying

Particle deposition behavior is critical to improve coating quality. Based on the Coupled Eulerian and Lagrangian (CEL) method, a three-dimensional multi-particle random deposition model was established, and grain inhomogeneity was introduced into the TC18 substrate. A polycrystalline model of the microstructure for the sprayed substrate was established by the Voronoi method. The evolution of the temperature, strain and stress fields during particle deposition was revealed, and the formation mechanism of pore defects was also analyzed. The results show that the overall strain of small particles is large, the core strain of large particles is small, and the edge strain is significant. The stress value near the large particles in the coating is large, while the stress at the edge of the coating is relatively small. The stress distribution of the TC18 substrate is similar to the uneven random geometric distribution of grains. On this basis, the response surface model of coating characteristics was established, the influence of process parameters on coating characteristics was analyzed, and the sensitivity of process parameters is determined. This research can provide a basis and guidance for engineering applications in related fields.