Synergistic effect of bismuth III sulfide and iron sulfide in the tribological performance of brake friction composite

Abstract

Metal sulfides play a major role in determining the friction and wear performance of the brake friction composites. The usage of the combinations of metal sulfides improves tribological performance compared to its individual metal sulfides in the formulation of friction material. In this work, the effect of the Bismuth III sulfide and Iron disulfide combination was evaluated against the tribological performance in the formulation of the friction materials. Six brake friction pads were developed by properly balancing the weight percentage of Bismuth III sulfide and Iron disulfide in the formulation. The tribological performance of the friction liners was studied using a chase tribo-meter following the IS2742 test protocol. The worn surfaces of the brake pad samples were examined for its surface morphology and elemental behaviour using a Scanning electron microscope and an Energy-dispersive x-ray spectroscope. It was observed that the partial replacement of the Bismuth III sulfide with Iron sulfide improves the friction and fade performance. The abrasive nature of the Iron sulfide in the friction pad increases the coefficient of friction and causes the high wear loss beyond the ratio of 4:6 of the mixed sulfides. A statistical approach named preference selection Index was employed to rank the brake friction materials based on the multiple performance criteria.