The effects of stacking fault energy on sliding wear behaviour of copper-aluminum alloys.

The addition of aluminum to copper results in a well-known reduction of stacking fault energy (SFE), which in turn enhances planar slip (i.e., restricts cross slip). The subsurface dislocation structure under stylus wear tracks was examined and those observations were correlated with the alloy SFE, and at the same time the surface topography of the wear track for correlation with the subsurface dislocation structure was examined using analytical electron microscopy (AEM). In addition, macroscopic unlubricated sliding wear rates were measured for these alloys as a function of aluminum concentration (i.e., SFE). The magnitude and nature of surface wear were examined using scanning electron microscopy (SEM). The relationship between wear-induced dislocation substructure, wear rates, and copper-aluminum alloy SFE is presented.