Development the flexible magnetic abrasive finishing process by transmitting the magnetic fields

Abstract

This research aims to present a novel approach in magnetic abrasive finishing to improve its potential for creating different finishing patterns in the free-form surface using no special fixtures or tool machines to minimize the complexity of the process. The key point of this idea is that magnetic abrasive particles can move in special patterns by transfer magnetic fields (similar to a magnetic train moving on a magnetic rail) and create the desired polishing patterns on the surface simultaneously. The coils are placed under a thin plate; then, a flexible magnetic path is created by a special arrangement of magnetic coils; after that, the coils are turned on and off in turn, and the magnetic abrasive particles move in the created path and abrasive the surface. The continuous movement of magnetic abrasive particles under the magnetic field will abrade the thin sheets’ surface. The tests were performed on copper sheets with a thickness of 1 mm. Experimental parameters include electric current (0.25, 0.5, and 0.75 A), speed of turning on and off of the coils (speed of magnetic abrasive particle movement) (20, 30, and 40 mm/s), and process time (1, 2, and 3 h). The experiments were performed on L-shaped and free-form sheets. The results show that using a transmission magnetic field in the MAF (TMAF) makes it easy to create different surface roughness patterns in different directions simultaneously. While in one part of the L-shape the electric current is 0.25 A, the surface roughness is around 0.90 µm, in the other part, where the electric current is 0.75 A, the surface roughness is around 0.49 µm. Meanwhile, TMAF makes it possible to finish a free-form surface with no special fixtures. Moreover, there is a direct relationship between the change in the surface roughness and the electric current and process time.