Finishing mechanism modelling on magnetic abrasive finishing behaviours with core-shell magnetic abrasive particles

Efficiency and precision are two key indicators in the magnetic abrasive finishing (MAF) process. This paper presents the design of a core-shell structured magnetic abrasive particles (MAPs) with enhanced magnetic saturation rate and improved morphology. In addition, a processing roughness model based on indentation theory was developed by determining the number of active abrasive particles within the MAPs. The evolution of the MAF mechanism during the elastic and plastic deformation of processing material is clarified to realise high MAF efficiency and precision on slender tube surfaces. The grooves that slot on magnetic poles drive the maximum magnetic force on the MAPs. The simulation results from both the theoretical model of magnetic force and the active abrasive particle number theory are consistent with the actual experimental parameters, which effectively predict and explain the MAF phenomenon and mechanism. As to the zirconium alloy tube, the maximum improvement of five MAF passes on surface roughness Ra using the designed MAP is 63.38%, with the roughness Ra reaching 0.119 μm.