Tribological Potencial of Zinc-Aluminium Alloys Improvement

Abstract

In this paper are presented result of the study aimed at tribological improvement of ZA alloys. Two treatments of ZA-27 alloy were used: a) T4 heat treatment and b) reinforcement by graphite. The heat treatment of samples included the heating up to 370 oC for 3 or 5 hours, quenching in water and natural ageing. Graphite particles reinforced ZA-27 alloy composite materials were obtained by the compocasting procedure, which was executed by mixing at the isothermal regime (460°C). Dry and lubricated sliding wear tests were conducted on as-cast and treated ZA-27 samples using block-on-disc machine over a wide range of applied loads and sliding speed. To determine the wear mechanisms, the worn surfaces of the samples were examined by scanning electron microscopy (SEM). The heat-treated alloy samples as well as reinforced samples attained significantly improved tribological behavior over the as-cast ones, both from the aspects of friction and wear.