Finite Element Analysis of Particle Impact on Substrates Using HVOF Thermal Spray Coating

Abstract

Lower flame temperature characteristics of high velocity oxygen fuel (HVOF) flame spray process favor several surface coating applications. Simulation of HVOF coating is extremely complex to analyze, since its properties and microstructure depend on numerous processing parameters. Finite element analysis (FEA) is used in this paper to analyze the influence of particle heat input and impact velocity on HVOF coating on various substrates. HVOF thermal spray coating conditions, Tungsten Carbide Cobalt (WC-Co) particles and steel substrate were modeled using ANSYS 14.5. Droplets of different size were considered as particles in the numerical analysis to study their impact on the substrate. Thermal and residual stress analysis was done on both the particle and substrate during different stages of the high velocity impact process. Both rigid and soft conditions of the particle and substrate were simulated. Thermal stress of both the particle and substrate were found to increase rapidly very close to the impact process. Smaller sized particles had higher plastic strain when compared to larger sized particles. However, the residual stress and plastic strain of the substrate increased when impacted by larger sized particles. Residual stress of both particle and substrate were found to be influenced by the impact and thermal stress of each other. Higher velocity of the flame spray showed improved plastic strain and stress on individual particles, which is a major reason for the dense pattern of coating.