Improved design of magnetorheological honing tool based on finite element analysis and experimental examination of its performance

The magnetorheological honing (MRH) tool is an advanced finishing tool which is designed and developed to superfinish internal cylindrical surfaces. It uses magnetorheological polishing fluid consisting of carbonyl iron particles and cutting-edge silicon carbide abrasives in viscous fluid medium. The MRH tool with retained polishing fluid is rotated and reciprocated inside a cylindrical workpiece within the gap between the outer surface of the MRH tool and the inner surface of the cylindrical workpiece called the working gap. Due to the relative motion between abrasives (gripped by carbonyl iron particles chains) and the workpiece's inner surface, finishing action takes place over the inner surface of the cylindrical workpiece. In this paper, two different designs of the MRH tool are designed with the same parameters based on finite element (FE) analysis using Ansoft Maxwell. The FE analysis results in more magnitude and uniformity of magnetic flux density in the working gap for the improved design of the MRH tool. Due to this effect, the abrasives are more strongly held with uniform strength which results in comparatively significant uniform finishing of the internal surface of the cylindrical workpiece. After confirmation of higher and uniform magnetic flux density on the improved MRH tool surface from FE analysis, two designs of the MRH tool are then fabricated with the same dimensions as taken in magnetic simulation. Experimentations have been performed with the fabricated finishing tools over the inner surface of cylindrical ferromagnetic workpiece of mild steel. The MRH tool with improved design results in uniform and more reduction in value of surface roughness with the same finishing time and process parameters as compared to the first proposed design. This confirms the enhancement in the finishing capability and better usefulness of the improved design of the MRH tool.