Anisotropic Microstructure Evolution of an AZ31B Magnesium Alloy Subjected to Dry Sliding and Its Effects on Friction and Wear Performance

Due to their hexagonal closed-packed (HCP) crystal structure, magnesium (Mg) and its alloys typically exhibit strong plastic anisotropy which gives rise to their orientation-dependent mechanical properties. Tribological performance in terms of friction and wear is of critical importance to manufacturing and applications of Mg alloys, particularly for components subjected to sliding motion. However, anisotropic microstructure evolution of Mg alloy and its effects on friction and wear properties have rarely been investigated. In this study, the orientation-dependent microstructure behaviors of an AZ31B Mg alloy during dry sliding were investigated. The coefficient of friction (COF) and wear rate of worn surfaces were analyzed and compared. The results indicated pronounced anisotropic friction and wear behaviors. The mechanism responsible for the anisotropic tribological behaviors was discussed.