Simultaneous improvement of microgeometry and surface quality of spur and straight bevel gears by abrasive flow finishing process

Abstract

This article reports on influence of extrusion pressure, abrasive particle size and volumetric concentration on simultaneous reduction of surface roughness and microgeometry errors of spur and straight bevel gear by abrasive flow finishing (AFF) process. A vertical configured experimental apparatus was developed for two-way AFF and developed fixtures for finishing gears. Experimental investigations were conducted to identify optimum parametric combination, using response surface methodology, based on Box–Behnken design approach. Results revealed that higher values of abrasive particle size and volumetric concentration yield more percentage decrease in surface roughness and microgeometry error. Roughness profile, bearing area curve, microhardness, surface morphology, and wear resistance of the gear having best quality finishing were studied. Surface morphology analysis of the flank regions of the best finished spur and straight bevel gears found them to be smooth and free from cracks and burrs. Reciprocating wear test results revealed higher wear resistance of the AFF finished gears as compared to the unfinished gears. AFF also enhanced microhardness of the finished gears, which would enhance their operating performance and service life. This study shows that AFF is a flexible, economical, productive, easy to operate, and sustainable nontraditional process for precision finishing of gear that can simultaneously improve microgeometry, surface finish, microhardness, surface morphology, wear resistance, and residual stresses of the finished gears. Gear manufacturers and users will be benefited by the outcome of this study. JEL codes: C00, C20