Modeling and simulation of the action mechanism of multi-particles in magnetic abrasive finishing for internal blind cavity using the discrete element method

This work aims to reveal the action mechanism of multi-abrasive particles in finishing the complex inner cavity. The body force function of particles and the particle-wall contact model were developed based on the theories of the magnetic field and the discrete element method (DEM). The particle motion and the wall-wear mode were simulated, revealing the influences of abrasive particle size, magnetic pole speed, and processing clearance on the finishing quality. Experiments verified the feasibility of the simulation. The result showed that when the processing clearance was 1 mm, the magnetic pole speed was 800 r/min, the finishing time was 40 min, and the steel grit (SG) diameter was 1 mm, the Ra was decreased by 89.3%. And then, 0.6 mm SGs were switched to perform the secondary polishing remaining other process parameters unchanged, and the Ra could be reduced to 0.95 mu m. The result can provide a practical research idea for polishing the inner cavity of special-shaped parts.