INFLUENCE OF FEED RATE ON SURFACE ROUGHNESS OF AL6088 ALLOY IN THE BALL BURNISHING PROCESS

Ball burnishing is a cold surface finishing process used to improve the roughness and other surface characteristics of aluminum alloys, resulting in enhanced wear, corrosion, and fatigue resistance. The process is based on the plastic deformation of surface irregularities using a hard, polished ball that is pressed against the workpiece under controlled forces. The key ball burnishing parameters that significantly influence the final surface roughness of aluminum include the applied force, burnishing speed, number of passes, and lubrication conditions. Studies have shown that multiple passes increase surface smoothness; however, beyond a certain threshold, additional passes do not yield substantial improvements due to saturation of plastic deformation. Moreover, moderate force levels (50–300 N) combined with low burnishing speeds (~0.05 mm/rev) have demonstrated the best results in reducing the surface roughness parameter Ra. Burnishing processes – including ball, roller, and diamond burnishing – are recognized as effective methods for enhancing the surface properties of aluminum alloys, particularly in terms of roughness reduction and hardness improvement.