Determination of Dry Wear Properties of Zn-30Al-Cu Bearing Alloys in Terms of Their Copper Content and Working Conditions Including Pressure and Sliding Velocity

Five Zn-30Al-Cu alloys were prepared by casting, and their dry wear properties were studied at selected ranges of contact pressure and sliding velocity with a block-on-disk-type tester after investigating their microstructure and mechanical properties. The hardness and the strength of the alloys increased, but their ductility decreased with copper content. The wear volume of the alloys increased with both pressure and sliding velocity, but their friction coefficient showed a slight decrease with pressure. Correlation of the experimental data indicated that the wear volume, friction coefficient and working temperature of the alloys could be determined in terms of their copper content and working conditions including applied pressure and/or sliding velocity. The equations showing the relationships between these properties and the variables are presented in Discussion section. Zn-30Al-3Cu alloy exhibited the second highest quality index and the lowest wear volume among the experimental alloys. Surface and subsurface layers formed in the wear samples of this alloy during the wear tests. Formation of these layers was attributed to the subsurface microstructural changes and adherence of the wear particles to the sample surface. Adhesion was observed to be the dominant wear mechanism for these alloys, but abrasion also played an important role in their wear behavior.