Tribological behaviour and worn out surface analysis of hot extruded Al-Si-Pb alloys

Abstract

The tribological behaviour of Al-Si-Pb alloys has been studied. Specimens of these materials were tested in both the as cast condition and a hot extruded condition. It was found that hot extrusion considerably improved mechanical properties of stircast Al-Si-Pb alloys and greatly decreased the porosity that was caused by powerful stirring in atmosphere conditions. The friction coefficient and wear rate decreased with increasing lead content, in particular the antiseizure properties of Al-Si-Pb alloys containing 20 and 25 wt-%Pb were improved remarkably. The reason is that a black compact film of lubricant was formed and covered almost the entire worn surface of specimens at highly applied load level. This film is a mixture of different constitutes containing Al, Fe, Si, O, and Pb.