Cavitation-erosion resistance of three zinc-aluminum alloy for bearing application

Zinc alloys are known as good competitors of copper alloys for some tribological applications, in both lubricated and dry conditions. In presence of lubricant, cavitation erosion phenomenon can occur, increasing the damaging of the part. In this paper a comparative study of the erosion resistance of an innovative (ZnAI15Cu1Mg) and two commercial Zn-AI alloys (ZA27 and Alzen305) is presented. Cavitation erosion tests were executed according to ASTM G32 on cast samples and the response of cach material was 055c55cd by measuring the worn volume as a function of cavitation time and by analyzing the damaged surfaces by means of optical and scanning electron microscope. It was pointed out that the new ZnAM 5Cu1Mg guarantees better resistance than the traditional ZA27 and Alzen305 as a consequence of the different microstructure.