Effect of Ultrasonic Burnishing Parameters on Burnished-Surface Quality of Stainless Steel After Heat Treatment

Abstract

AbstractUltrasonic burnishing induces beneficial compressive stresses and high surface quality in components with contact as a functional requirement. It was observed in previous work that some burnishing parameters can hinder burnishability of stainless steels. In this research tangential misalignment angles (TMA) for burnishing were varied considering as-supplied and heat-treated stainless steel. Properties such as surface hardness and surface roughness were measured after burnishing process. Electron Backscatter Diffraction was performed to characterize microstructure using Matlab (MTEX) to calculate average grain areas. By changing burnishing parameters, i.e., shaft rotational speed and burnishing tool diameter, it was observed that burnishing was less successful. Nevertheless, significant improvement in burnished surface quality was observed after heat-treatment process. In addition, grain size characterization revealed mean grain area reduction from 26 µm2 for unburnished to 11 µm2 and 3 µm2 for burnished and heat-treated samples respectively. Most importantly this work reveals the enhanced possibility of burnishing stainless steels after heat-treatment with varying tangential misalignment angles.