Abrasive wear behaviour of aluminium hybrid nanocomposites produced by ultrasonication assisted casting method

Abstract

In this investigation, the abrasive wear resistance of Al/ (B4C+SiC) hybrid nanocomposites was tested against hard SiC abrasive sheets and compared to those of unreinforced Al alloy. Three loadings of nano-SiC (0.5, 1.0, and 1.5 Wt. %) and one loading of nano-B4C (0.5 Wt. %) were mixed with an aluminium alloy to produce the aluminium hybrid nanocomposites using an ultrasonication assisted casting method. Scanning electron microscopy showed a uniform distribution of nanoparticles in the Al alloy. Transmission electron microscopy indicated an increase in the dislocation density of nanocomposites compared to monolithic Al. The abrasive wear experiments were conducted on a Pin-on-Disc tribometer using pins of 9 mm diameter and 15 mm height under dry sliding conditions at room temperature. The wear rate in terms of wear volume per unit weight was calculated for both unreinforced alloy and hybrid nanocomposites. It was observed that Al hybrid nanocomposites showed superior wear resistance properties compared to the unreinforced sample. The nanocomposite with 1.5 Wt.% nano-SiC and 0.5 Wt.% nano-B4C possessed better wear resistance properties compared to the other composites tested in this work. The worn out surface of the Al alloy and its hybrid nanocomposites imply that the wear mechanism is through plowing action on the surface by SiC abrading particulates. The nanocomposite with 1.5 Wt.% SiC and 0.5 Wt.% B4C showed 88.32 % increase in wear resistance compared to the monolithic Al. This combination of material can be selected for abrasive wear resistance applications.