Effects of Resin Type and Fiber Length on the Mechanical and Tribological Properties of Brake Friction Materials

In this study, the effects of resin type and fiber length on mechanical properties and friction characteristics of automotive brake materials were studied. Three types of resin, viz. straight phenolic resin (SR), cashew nut shell liquid modified resin (CR), and melamine resin (MR) were used as matrix material. Lapinus with different lengths was used as inorganic fiber. Three series of friction composites composed of nine composites in the form of brake materials were manufactured. Physical, mechanical, and tribological properties of all composites were investigated. The friction tests were performed using a Chase type friction tester. The results showed that both resin type and fiber length played an important role on the mechanical and tribological properties of the friction materials. The highest and the lowest friction coefficient for resin types were recorded for SR and MR composites, respectively, while MR and CR composites showed the highest and the lowest wear resistance, respectively. For the fiber length considered, increasing the fiber length increased the wear resistance of the composites. The coefficient of friction, in general, showed a good correlation with the wear resistance of the composites. But, there was no clear correlation with the mechanical and tribological properties of the composites. The morphological features of worn surfaces and wear debris of the composites were analyzed in order to understand the friction and wear mechanisms of this tribosystem.