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

Abstract

Ultrasonic 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.

Effects of ultrasonic burnishing on the surface quality of corrosion-resistant tool steel using a hard-carbon-coated burnishing tool

“…For the tool oriented 90° to the shaft, TMA is considered as 0 and it can increase on either side -hence positive and negative TMA are possible. It is important to study TMAs, since in burnishing process, one semi-spherical (burnishing tool) and a cylindrical surface get in contact with each other and double curved surfaces [2] could form. Beside the possible effect on cylindricity, surface roughness can be vary significantly [2].…”

“…It is important to study TMAs, since in burnishing process, one semi-spherical (burnishing tool) and a cylindrical surface get in contact with each other and double curved surfaces [2] could form. Beside the possible effect on cylindricity, surface roughness can be vary significantly [2].…”

“…In our previous work [2], burnishing was performed on Stavax stainless steel using a wolfram carbide ball with a finishing head 6 mm in diameter. The Ta-C structured hard-carbon coated-tool used in this research is known commercially as BALINIT® MILUBIA [15].…”

“…The tool feed and burnishing frequency of the tool head were kept constant, as in Fig. 1 [2]. With this configuration, burnishing was only possible at 0° TMA, while a higher TMA resulted in deteriorated surfaces.…”

“…Introduction Ball burnishing and other forms of burnishing methods have gained popularity in recent years, as they not only affect the workpiece surface but also improve both the physical and mechanical properties of turned parts [1]. The goal of all burnishing methods is to create surface layers of high quality to improve the surface properties of mechanical components, such as surface roughness, hardness residual stress, and microstructure in different applications that require an excellent surface finish and dimensional accuracy [2,3]. Such methods are mainly used on rotating components with high-quality requirements, such as automotive axles, bearing parts, or crankshafts [4].…”