Tribological characterisation in dry sliding conditions of compocasted hybrid A356/SiCp/Gr(p) composites with graphite macroparticles

The influence of SiC microparticles reinforcement and graphite macroparticles addition on the friction and wear characteristics of A356 Al-Si alloys, produced by compocasting, has been assessed using a pin-on-disc tribometer. The incorporation of SiC reinforcement increased the coefficient of friction and reduced the wear. The addition of graphite did not reduce the coefficient of friction. In the case of hybrid composite with 1wt% graphite, wear was more or less the same as with SiC reinforced composite, while in the case of hybrid composite with 3wt% graphite, wear was further reduced. On the worn surfaces of hybrid composites, the presence of the discontinuous mixed surface layer, containing graphite and transferred counter-body material, was noticed