Numerical and experimental investigations on the effect of particle properties on the erosion behavior of aluminum alloy during abrasive air jet machining process

In this study, experimental and numerical investigations have been done to explore the effect of the particle properties on the erosion behavior of aluminum alloy during the abrasive air jet machining (AAJM) process by using the novel medium-hard amino thermoset plastic (ATP) and conventional super-hard alumina (Al2O3) particles. In the numerical simulation, a novel linear elastic material model with the failure standard was proposed to define the ATP particle and the conventional rigid material model was used to define the Al2O3 particle. Meantime, the smooth particle hydrodynamics (SPH) interpolant with the moving-least-squares method was used to establish the impact target model. Then, a multi-particle impact model based on the SPH and finite element coupling method (SPH-FEM) was further developed to investigate the particle impact process. It indicates that the SPH-FEM method can be used to simulate the erosion behaviors of the aluminum alloy during the AAJM process by using not only the super-hard Al2O3 particle but also the medium-hard ATP particle, and the simulation results are fundamentally consistent with the experimental ones. The results demonstrate that the effect of particle hardness on erosion behavior is much greater than that of compressive air pressure. Furthermore, there exists an optimal impact angle where the surface material can be removed by chip formation resulting in the maximum material removal rate, and the surface erosion behavior can be accurately predicted by simulation. Moreover, with the particle hardness increasing, the optimal impact angle would be reduced accordingly.