A magnetic abrasive finishing (MAF) platform utilizing horizontal transverse magnetic field magnetized by permanent magnets

Abstract

In this study a magnetic abrasive finishing (MAF) platform was developed by which an innovative MAF tool design was verified. The platform was composed of a tool per se, a linear moving table where a specimen placed on it, and a slurry supplying pump. The magnetic field was provided by two sets of NdFeB permanent magnets placed with opposite directions inside the tool. By using a C-shape and taper structure of low carbon steel, the magnetic flux generated by the magnets formed a magnetic circuit and was directed and concentrated at the opening notch of the C-shape structure where the tool tip was. A slurry composited of magnetorheological (MR) fluid, abrasive particles, and silicon oil was served as a MR abrasive slurry. The slurry was propelled to the tool tip by the slurry supplying pump and was then magnetized there to form a magnetic brush. While the table moved relative to the tool the magnetized slurry scrubbed a specimen on it. It is observed that after 2 ~ 3 hundreds of times of reciprocating motions, the magnetic brush would be stiffened and a highly efficient finishing machining process could be achieved. With aluminum specimens of initial surface roughness of Ra ~ 0.5 μm as examples, it is demonstrated that a fine surface of Ra ~ 0.06 μm could be achieved in about 2 ~ 3 min.