Tribological investigation of copper and AISI 304 steel during dry sliding wear

Abstract

Copper-based metal matrix (CBMM) composite is used in ball bearings and other tribological components due to significant improvement in thermal and mechanical properties. However, copper alloys based bearings are likely to fail due to severe surface fatigue wear in rolling/sliding condition. To understand the fatigue wear of copper-alloy which is dominated by the evolution of asperity characteristics, the study of topography evolution in dry sliding condition is essential. The purpose of this study is to study the tribological behavior of copper-steel material combination in dry sliding condition. The tribological properties of copper are also compared with AISI 304 steel. Experiments are performed on pin-on-disc tribometer. The AISI 52100 steel disc is used as a counter body during the experiments on AISI 304 and copper pin materials. The effect of normal load on friction coefficient and wear is studied. Surface topographies of the worn surfaces are measured using a 3D optical profiler. Scale-sensitive fractal analysis (SSFA) is performed on worn surfaces to analyze the complexity of the surface. It is found that surface complexity increases with an increase in normal load. At low scale, worn surfaces are rough and can be simplified by applying fractal theory. At lower load, an oxide layer is formed on the copper surface which reduces the direct asperity contacts. At higher load, distortion in the shape of autocorrelation is observed due to an increase in adhesion and plowing wear.