Investigation of mechanical and tribological properties of MoS ₂ -reinforced AZ91D nanocomposites

Nanocomposites reinforced with MoS 2 offer strong potential for lightweight engineering applications, yet AZ91D magnesium alloy faces limitations in strength and wear resistance. This study overcomes these issues using an ultrasonication-assisted stir-squeeze casting method to improve wettability, densification, and uniform distribution of MoS 2 . AZ91D composites with 0.5, 1 and 1.5 wt.% MoS 2 were fabricated and examined through microstructural, XRD, density, porosity, mechanical and tribological tests. Results showed refined grains, uniform nanoparticle dispersion and mechanical properties improved significantly up to 1 wt.%. TOPSIS, ANOVA, and RSM optimisation showed that the 1 wt.% composite made the biggest significance (82%). The optimal conditions yielded major reductions in wear rate (61.7%) and COF (44%). Confirmation tests validated the predictions, establishing 1 wt.% MoS 2 as the optimal for enhanced performance.