Friction and Wear Characteristics of Hot-Rolled Al7075-TiO2-Graphite Hybrid Composites

This paper investigates the effects of titanium dioxide and graphite hybrid reinforcement inclusion, as well as hot rolling, on the microhardness, microstructure, and friction–wear behaviour of a hybrid composite based on Al7075. Stir casting and hot rolling were utilised to develop hybrid composites composed of Al7075 dispersed with titanium dioxide and graphite. Microstructural examinations using a scanning electron microscope confirmed the existence of reinforcement particles and their orientations in the rolling direction. The wear test of hot-rolled and as-cast hybrid composites was conducted using an ASTM G99 pin-on-disc arrangement under dry sliding conditions. In terms of wear resistance and coefficient of friction, hot-rolled samples surpassed cast samples under all load and sliding conditions examined. Utilising SEM, the wear mechanisms of cast and rolled alloys, as well as hybrid composites, were analysed.