Mechanical and wear behaviour of Zn-27Al based composites reinforced with particulate mixes of quarry dust, silicon carbide and graphite

The mechanical and wear properties of Zn27Al alloy based composites reinforced with silicon carbide (SiC), quarry dust (QD) and graphite (Gr) particles were investigated. Double stir casting was used to produce the composites which contained 7 mass % reinforcement with varied mixtures of QD, Gr and SiC. Microstructural analysis, mechanical and wear tests were used to characterize the composites. The results show that the hardness of the composites increased with the addition of the reinforcements, but decreased marginally with increase in QD and Gr particles. The tensile strength of the composites with a mix of SiC and QD were on the average higher than the tensile strength of composites with a mix of QD and Gr, but the tensile strength decreased with increase in QD and Gr particles. The percent elongation of the composites improved with increase in concentration of QD particles in the reinforcement phase but was invariant to the concentration of Gr particles. Fracture toughness of the SiC and QD reinforced composites did not follow a consistent trend and were lower than that of the composites reinforced with QD and Gr. The wear resistance of the Zn-27Al based composites basically improved with the addition of QD and Gr particles.