Tribological properties of aluminium-clay composites for brake disc rotor applications

In this paper, the mechanical and tribological behaviours of various compositions of aluminium 6063 alloy – clay (Al-clay) composites for brake pad applications were studied. The Al-clay composites with 5-30 wt.% of clay particles of grain size of 60 BSS (250 microns) were developed through stir casting route. The wear characteristics of Al-clay in dry sliding conditions were subjected to a series of Denison T62 HS pin-on-disc wear tests. The action of two different loads (4 and 10N), three sliding speeds of 200, 500 and 1000 rpm were investigated. The results of the mechanical and wear tests as well as the metallographic investigation of optical, scanning electron microscopy and energy dispersive X-ray microscopy revealed an improvement in the tensile strength, hardness and wear resistance in the composites with 10-25 wt.% clays. The best values were obtained at 15 wt.%. Wear rate was highly influenced by applied load and sliding speed. The developed composites with 15-25 wt.% clay addition were similar to conventional semi metallic brake pad in terms of wear and friction properties.