Characterization and Mechanical Behavior of Fly Ash-Alumina Reinforced Zn-27Al Alloy Matrix Hybrid Nanocomposite Using Stir-Casting Technique

This paper reports the viability of developing Zn-27Al alloy matrix hybrid nanocomposites reinforced with alumina, graphite and fly ash (solid waste bye product of coal in thermal power plants). This research work was aimed at developing low cost-high performance Zn-27Al matrix nanocomposite with low density. Alumina particulates (Al2O3), graphite added with 0, 2, 3, 4 and 5wt% fly ash were utilized to prepare 10wt% reinforcing phase with Zn-27Al alloy as matrix using two-step stir casting method. Density measurement, estimated percentage porosity, tensile testing, micro hardness measurement and optical microscopy were used to assess the performance of the nanocomposites produced. The results show that the hardness, ultimate tensile strength, and percent elongation of the hybrid nanocomposites decrease with increase in fly ash content. The maximum decrease in hardness and ultimate tensile strength of 13.72% and 15.25% respectively were observed for composite grade containing 5wt% fly ash. The percentage elongation of composite sample without fly ash is 8.9% which is comparable with that of the sample containing 2wt% fly ash with percentage elongation of 8.8%. The results show that fly ash can be utilized as complementary reinforcement in ZA-27 alloy matrix composite to reduce cost.