High-quality surface polishing of selective-laser-melting stainless steel by defoamed magnetorheological elastomer

Abstract

Thanks to the controllability of mechanical properties by the applied magnetic field, magnetorheological elastomer (MRE) polymers have demonstrated promising application prospects in high-quality surface polishing. To clarify the influence of the inner pores on the mechanical performance, four silicone rubber-based MRE polymers were manufactured by adding different contents of defoaming organosilicons. First, the surface and section microstructural features were observed on an ultra-deep microscope to evaluate the defoaming effect. Second, the energy storage modulus of the MRE polymers containing different contents of organosilicons was measured on a dynamic mechanical tensile device by changing the strength of the applied magnetic field. Third, the MRE polymers were fabricated into four MRE polishing pads and used for the surface polishing of selective-laser-melting 022Cr17Ni12Mo2 stainless steel workpieces on a DMG 5-axis machining center. Compared with the surface treated by the MRE pad without organosilicons, the surface quality of the workpiece polished by the MRE pad with 0.99 wt‰ organosilicons was improved by 45.4%, and the Ra reached 23.80 nm. The relationship between the energy storage modulus of the defoamed MRE polymers and their polishing capability was also discussed.