Nanowear Mechanisms of Mg Alloyed with Al and Y at Elevated Temperatures

We examine the role of important alloying elements (Al, Y), on friction and wear mechanisms of Mg as a function of temperature. Friction and wear tests of Mg–5%Al and Mg–5%Y alloys performed at room temperature, 100 °C and 150 °C reveal that addition of Al and Y significantly reduces the coefficient of friction. However, despite higher hardness of Mg–5%Y alloy, its wear rate was found to be higher than Mg–5%Al alloy at elevated temperatures. We show that this behaviour, observed for Mg–5%Y alloy at elevated temperature, can be attributed to its higher surface energy than Mg–5%Al and pure Mg, leading to enhanced adhesive wear, which is detrimental to tribological applications.