Development of a new Ultra-precision magnetic abrasive finishing process

Abstract

This study was performed to develop a new ultra-precision magnetic abrasive finishing process. This process uses a new type of "magnetic abrasive slurry" made by mixing super-minute spherical iron particles, super-minute abrasive grains, and oily grinding liquid. When internal finishing was performed, the stirring phenomenon of the magnetic abrasive slurry occurred, and super-minute abrasive grains and minute iron particles were uniformly distributed in the magnetic abrasive slurry. Thus, a super-precision internal tube surface could be created. Internal magnetic finishing experiments of SUS304 stainless steel tubes were performed with a magnetic abrasive slurry consisting of spherical carbonyl iron particles (6μm in mean diameter) and diamond abrasive grains (0 - 0.25μm in mean diameter). The results indicated successful creation of an ultra-precision internal surface, and it was confirmed that the initial surface roughness of 320 nm Ra could be improved to 5 nm Ra.