Effect of HVOF particle deposition angle on particle deposition behaviour

Abstract

Power particles are mainly in solid state prior to impact on substrates from high velocity oxy-fuel (HVOF) thermal spraying. The combination state of particles and substrate significantly affects the coating quality. Finite element analysis (FEA) models are developed to simulate the impingement process of solid particle impact on substrates under different deposition angles. This numerical study analyzes the deformation behavior of particles and the reason under different deposition angles, and the shear-instability– based method is applied to the particles. The particles are given the properties of widely used WC-Co powder for HVOF thermally sprayed coatings. The numerical results confirm that in the case of vertical deposition, the deposition behavior of particles is better than that of non-vertical deposition. In the case of non-vertical deposition, the equivalent plastic strain of the right part of the particle central axis is larger than that of the left part of the central axis, and decreases gradually in a clockwise direction. The flattening process of particles is mainly controlled by the horizontal drag force. When the normal velocity of particles exceeds the critical deposition velocity, the particles will appear adiabatic shear instability phenomenon, with the matrix to produce an effective combination.