Effect of ball burnishing on surface roughness and wear of AISI 316L SS

Abstract

This work aims at the improvement of surface quality and wear resistance of AISI 316L stainless steel, used in different industrial sectors including orthopedic applications. Ball-burnishing treatment, considered as a very efficient mechanical finish process, was applied with respect to the response surface method. Surface roughness parameter Ra was minimized by using a mathematical model based on Box–Behnken model and expressing Ra as a function of applied charge, feed rate, and ball diameter. After optimization, the selected regime was fixed and the number of passes was increased by up to 5. Ra was measured again and tribological behavior was studied. Results show that surface roughness of best burnished sample can be decreased to a value much less by 93.4% and correspondingly, its wear loss can be improved by 53.4%, but with respect to fix 3 passes during ball burnishing. Morphologies of wear scars analyzed by scanning electron microscopy specify that adhesive wear occurred in both untreated and burnished surfaces. The coefficient of friction, measured under dry conditions, was reduced only for the smoothest surface, while other specimens had elevated coefficient of friction compared to turned surface.