Microstructural and Tribological Evaluation of LM26 Aluminum Hybrid Composites Reinforced with Almandine Garnet and MoS₂

This study investigates the mechanical and tribological performance of LM26 aluminum alloy and its hybrid composites reinforced with almandine garnet and MoS 2 . The composites were fabricated using a bottom-pouring, two-step stir casting method with almandine garnet reinforcement ranging from 5 to 20 wt.% and MoS 2 from 1 to 4 wt.%. Sliding wear tests performed on a Linear reciprocating tribometer, analyzed through Taguchi optimization, confirmed that this composition also achieved the lowest wear rate. Microstructural examination revealed uniform reinforcement dispersion, almandine garnet and MoS 2 surface coating formation, and temperature-induced oxidation influencing wear progression. Among the developed composites, the specimen reinforced with 5 wt.% almandine garnet demonstrated the most balanced combination of mechanical strength and overall performance. However, Taguchi optimization of tribological parameters identified the composite containing 20 wt.% almandine garnet and 4 wt.% MoS₂ as the optimum configuration for minimizing wear. The optimal parameter combination was obtained at A1B1C1D1E4, corresponding to Load (A1) = 20 N, Frequency (B1) = 20 Hz, Stroke Length (C1) = 2 mm, Temperature (D1) = 50°C, and Filler Content (E4) = 20 wt.%, achieving an optimization accuracy of 98.76%.