Influence of quarry dust-silicon carbide weight percentage on the mechanical properties and tribological behavior of stir cast ZA-27 alloy based hybrid composites

This research aims at investigating the influence of quarry dust (QD)-silicon carbide (SiCp) particles weight percentage on the mechanical properties and wear behavior of ZA-27 alloy based hybrid composites. The ZA-27 alloy hybrid composites containing 8 wt% and 10 wt% QD-SiCp with varied weight percentage of 0, 25, 50, 75 and 100% quarry dust respectively was produced using stir casting technique. Microstructural evaluation, density measurement, estimated percentage porosity, mechanical properties evaluation and wear evaluation were used to assess the performance of the produced composites. The results show that the microstructures of the produced composites are similar, displaying a somewhat feathery feature which is the dendritic structure of the ZA-27 alloy matrix with homogeneous dispersion of the reinforcing particles. The density of the composites decreased with increase in the weight percent of quarry dust (corresponding to decrease in weight percent of SiCp) while slight voids exist as compared to the unreinforced alloy. The hardness and tensile properties of the composites improved showing similar trend as quarry dust increases to maximum addition of 75% for both the 8 and 10 wt% composites grade; there is consistent increase in fracture toughness with exception of composites containing 50% stone dust which showed slight decrease in both the 8 and 10 wt% composites grade while superior wear behavior in terms of wear loss was observed for hybrid composites over the unreinforced and SiCp single reinforced alloys for both 8 and 10 wt% composite grades. Keywords: ZA-27 alloy based composites, Microstructure, Mechanical properties, Wear behavior, Quarry dust, Silicon carbid