Potential use of fly ash and bagasse ash as secondary abrasives in phenolic composites for eco-friendly brake pads applications

Abstract

Brake pad is the essential component of disk brake in automotive applications that is made of phenolic-based composites. The alumina and silica are often used as primary abrasives in brake pads. In this study, we investigated the hardness, compressive, friction and wear properties under room temperature and elevated temperatures (100°C and 150°C) of phenolic-based composites containing the natural ashes of fly ash and bagasse ash as secondary abrasives, which ranged from 0 to 12 wt%, for replacing primary abrasives. The results suggested that 4 wt% secondary abrasives was recommended for optimization of the overall properties of the composites. It was found that all composites exhibited the abrasive wear behavior evidenced by wear debris between the counterfaces acting as third-body abrasives. The phenolic-based composites at 100°C and 150°C had higher coefficient of friction and lower wear resistance than those at room temperature. The incorporation of bagasse ash resulted in more compression for a given load than that of fly ash. In summary, the fly ash and bagasse ash, which were natural ashes, showed a potential use as secondary abrasives in the phenolic-based composites for eco-friendly brake pads.