Synthesis, microstructure and mechanical properties of Al-Si-Mg alloy hybrid (zircon plus alumina) composite

In the present work, a detailed study of zircon and alumina reinforcement in to the matrix of Al-Si-Mg alloy on the microstructure and wear behavior has been carried out. To study the effect of reinforcement on the wear behaviour of these composites, the alloy is reinforced with different amounts of zircon and alumina particles limiting to the total 15 wt%. The microstructure of these hybrid composites reveal uniform distribution of the reinforced particles. Composites are found to exhibit better hardness and wear resistance compared to base alloy. Among the different composites, the one reinforced with 3.75 wt% of zircon and 11.25 wt% of alumina particles (composite B) is found to be the best combination exhibiting high hardness and low wear rate at a test load of 15 N. SEM analysis of worn surface of hybrid composites shows no evidence of plastic deformation of matrix phase. Abrasive wear mechanism and particle pull out is the common feature observed from all the composites.