Experimental investigations into internal magnetic abrasive finishing of pipes

Abstract

Surface finish is one of the important parameters that affects functional aspects of an assembly like friction between mating parts and wear resistance. Magnetic abrasive finishing is one of the advanced finishing processes which has the ability to produce nano-finished surface by removing material in the form of microchips. The present paper introduces a novel tool based on magnetic abrasive finishing (MAF) principle for polishing holes, blind holes, grooves, and vertical surfaces. The tool designed and developed in the present study consists of two permanent magnets with their similar pole facing each other, such that a high magnetic flux density is achieved around the circumferential area between the magnets and the same has been simulated using Maxwell software. In order to evaluate the performance of the tool, experimentation based on central composite design (CCD) technique was performed to finish stainless steel (SS304) pipe. The results so obtained were analyzed to study the effect of process parameters like rotational speed, magnetic flux density, abrasive size, and abrasive weight percentage on percentage change in surface roughness. The analysis showed that the magnetic flux density was the most effective parameter while finishing the stainless steel (SS304) pipe followed by rotational speed. Experimentation at an optimized condition resulted in a surface finish of 56 nm. Further SEM images were taken to understand the surface morphology of finished surface.