Experimental Investigations on Simultaneous Finishing of Surfaces with Abrasive Flow Machining

Abstract

Abrasive flow machining (AFM) is a non-traditional finishing process used to deburr, chamfer, polish, remove recast layers, and to produce compressive residual stress. AFM can be mostly used to polish and deburr internal parts, through holes, intersecting holes and freeform surfaces which are difficult to finish with other traditional finishing processes. It can be a high potential candidate in the simultaneous finishing of the workpiece, instead of separately finishing of internal and external surfaces of the workpiece with other non-conventional processes. The present research initiatives are based on the simultaneous finishing of the ring-shaped cylindrical aluminum alloy workpiece. For accomplish the main objective of the simultaneous finishing of the workpiece the fixture setup is designed and fabricated. The hydraulic system of a Universal Testing Machine is used for actuation of the media piston in the present work. The present study initiatives identify the process parameters such abrasive mesh size, concentration of abrasives in media and number of passes that significantly affect the change in surface roughness of the inner, outer and side surfaces, and the amount of material removal. The L27 full factorial design has been adopted in the present study for the optimization of the experimental study. Experimental investigations have been carried out on the abrasive flow machining setup designed and developed by the author. The silicon polymer abrasive media has been prepared. The parameters selected for the present study is abrasive mesh size, concentration of abrasives in media and number of passes at three level each. Work material, abrasive type, working temperature, media, media flow per pass, the polymer to gel ratio was kept constant in the present investigation. It has been observed from an experimental investigation that the abrasive mesh size, concentration of abrasives in media and number of passes have a significant effect on both changes in surface roughness and material removal. The percentage improvement in surface roughness of the internal, external and side surface of the ringshaped workpiece are observed in this study are 35, 37 and 27% respectively. The main objective of the simultaneous finishing is achieved by the specially designed fixture and the same objective may be applied for simultaneous finishing of the workpiece, specifically deep groove ball bearing in one go instead of separately finishing of internal and external surfaces with traditional finishing processes.