Optimizing Tribological and Mechanical Properties of Hypereutectic Al–Si Alloys Through Advanced Grain Engineering and Graphene Reinforcement

Current research investigates adding grain refiners and modifiers affect the mechanical and wear properties of a cast hypereutectic aluminum silicon alloy. Die casting produced samples from five different compositions, including grain refinement alone, grain modification alone, simultaneous grain refinement and modification, and graphene reinforcement. A composition with 0.05 wt% Ti as a grain refiner, 0.05 wt% Sr as a grain modifier, and 5 wt% graphene as reinforcement showed significant improvements in mechanical and tribological properties compared to the other four compositions. This enhancement results from finer, denser α-Al dendrites and structure of silicon in an aluminium solid solution matrix with dispersed graphene particles. Lower friction and large grained microstructure also reveal tribular formation, although the tribular formed through different initial microstructure processes. The superior tribological properties demonstrate the effectiveness of the developed alloy system. Potential applications include automotive and aerospace components where tribological properties are critical, especially engine components.