Effect of WS₂ Nanotubes on the Mechanical and Wear Behaviors of AZ31 Stir Casted Magnesium Metal Matrix Composites

In this study, the AZ31 magnesium alloy was reinforced with tungsten disulfide (WS₂) nanotubes to fabricate the nanocomposite using the stir casting method. The microstructural analysis, mechanical and wear behaviors were investigated with the effect of WS₂ on the AZ31 alloy. Scanning electron microscopy (SEM) was used to conduct the microstructural analysis. The microstructures are revealed to incorporate the aluminum content with the WS₂ nanotube, disclose the presence of the secondary phase, which was increased compared with the AZ31 alloy and was detected by energy dispersive spectroscopy (EDS). The mechanical properties of hardness and yield strength (YS) were significantly improved with the addition of WS₂ nanotubes. This is mainly due to the strengthening mechanisms of Orowan, the coefficient of thermal expansion (CTE) mismatch and the load transfer mechanism. The theoretical YS was calculated and compared with the experimental results. However, the ultimate tensile strength (UTS) and the fracture strain were decreased with the addition of reinforcement which might be owing to the clustering of nanotubes. Finally, the wear behavior of the wear weight loss and depth of cut was investigated. This test revealed that the addition of WS₂ nanotubes reduced the weight loss and depth of the material cutting that was mainly due to the presence of hard WS₂ nanotubes.