Development of a New Ultra-Precision Magnetic Abrasive Finishing Process

Abstract

To obtain an ultra-precision surface, this research developed a new type of magnetic finishing tool, “Ultra-precision Magnetic Abrasive Slurry”, for a magnetic field assisted internal finishing process. This ultra-precision magnetic abrasive slurry is made to mix simply the super-minute abrasive grains, super-minute globular iron particles, and oily grinding liquid. When the internal finishing was executed, the automatic mixing phenomenon of the Ultra-precision Magnetic Abrasive Slurry is caused, at the same time, super-minute abrasive grains and minute iron particles were uniformly distributed to the magnetic abrasive slurry. It was confirmed that a smooth mirror internal finishing for a SUS304 stainless steel tube is able to be achieved, by using the Ultra-precision Magnetic Abrasive Slurry that consists of the globular carbonyl iron particles (6μm in mean diameter) and diamond grains (0.25~0.75μm in mean diameter) and the oily grinding liquid. In this study, we examined the influence that the rotational speed of the magnetic pole exerted on the finishing characteristic. The results showed that the ultra-precision surface is successfully made, and the surface roughness has been improved from 320nm Ra to 3.37nm Ra .