Experimental investigations into nanofinishing of Ti6Al4V flat disc using magnetorheological finishing process

Abstract

3-D components used in today’s industries need fine surface characteristics as a functional requirement. Therefore, it is necessary to improve surface characteristics before putting them into useful applications, by achieving superior surface finish very close to dimensional precision. Magnetorheological fluid-based finishing processes are efficient in achieving ultrafine surfaces. This paper aims to explore the key quality performance of the magnetorheological finishing process in achieving nanolevel finish on Ti6Al4V discs. Sequential experimental design through statistical design of experiments was employed and response surface model was developed. Concentration of abrasive particles and wheel speed were considered as independent process parameters for the present study. To have uniform (or minimum variation) surface roughness values on the entire surface, a negative replica of the workpiece has been fabricated as a tool, and magnetic field was used to create magnetorheological effect. Using a template, surface roughness was measured at the same points before and after finishing. Initial Ra value was found to be the critical process parameter for finishing Ti6Al4V workpiece by magnetorheological finishing. % change in Ra is significantly affected by concentration of abrasive particles (≈50%) followed by initial Ra (≈ 38%). Finishing rate is significantly affected by initial Ra (≈61%) followed by concentration of abrasive particles (≈33%). An area roughness of 49 nm was achieved in the present study.