Numerical simulation of in-flight particle oxidation during thermal spraying

Metal powders are widely used for thermal spray coating to improve wear, corrosion and temperature resistance of products. The high thermal profiles endured for sprayed particles give rise to oxidation on the surface of metal powders. Metallic oxides are brittle and undermine the performance of coated products. To understand the growth of oxide layers on in-flight metal powders, an oxidation model is implemented into the Lagrangian formula of particle tracking. The numerical simulation is achieved for a 3D combusting gas flow generated by a high velocity oxygen fuel (HVOF) thermal spray gun. The results are able to demonstrate the correlation between in-flight particle oxidation and operation parameters.