Mechanical and Wear Properties of Al–Al2O3 Metal Matrix Composites Fabricated by the Combined Effect of Stir and Squeeze Casting Method

摘要

The effects of nano particles on double shear strength and tribological properties of A356 alloy reinforced with Al2O3 nano particles of size 30 nm were investigated. The percentage inclusions of Al2O3 were varied from 0.5 to 1.5 wt%. The particles were added with stirring at 400 rpm and squeeze casting at 750 °C and pressure of 600 MPa in a squeeze casting machine. Comparison of the performance of as cast samples of A356/Al2O3 nano composite was conducted. The tribological properties of the samples were also investigated by pin-on-disk tests at 10, 30 and 50 N load, sliding speed 0.534 m/s and sliding distance 1100 m in dry condition. SEM images of microstructure analysis of the composite, Al2O3 (0.5 and 1 %) particles were well dispersed in the A356 alloy matrix. Partial agglomeration was observed in metal matrix composite with higher (1.5 %) Al2O3 particle contents. The nano dispersed composites containing 0.5 and 1 wt% of Al2O3 nano particles exhibited the highest double shear strength, lesser wear loss and coefficient of friction.