Investigation of interference effects on the burnishing process

Abstract

Machining of critical components such as turbine compressor and pump parts is required to generate compressive residual stress on the surface layer in order to obtain high fatigue life. As an effective method to generate and improve the compressive residual stress of machined parts, burnishing has been widely used in industry. Despite its importance, few studies have investigated the mechanism of burnishing on surface residual stress. In this paper, the interference effects due to nearby burnishing points were revealed and investigated in the context of an elastic burnishing tool. The interference effects during the burnishing process help to enhance the compressive residual stress and improve the distribution of compressive residual stress on the burnished surface layer. In order to analyze the mechanism behind the interference effect more clearly, a 2D finite element model of the burnishing process was developed. It was found that the interference effect exists and becomes stronger as the feed rate is decreased. Small feed rates show a more apparent effect on the enhancement of interference effects. The results indicate that the interference effect of the workpiece surface is mainly created by the influence of the preceding burnishing points on the future burnished surface.