The effect of disc surface hardness on the tribology and emission behaviors of brake materials

Abstract

Effects of disc surface hardness on brake wear particle emissions were investigated using grey iron discs with various surface hardness under urban braking conditions. Three types of brake materials-low-metallic, non-asbestos organic, and semi-metallic, were used as counterparts. Results indicate that disc surface hardness significantly influences the morphologies and elemental compositions of contact plateaus on the brake material surface, as well as tribology performances and brake wear particle emissions of brake materials. Lower friction coefficients, specific wear rates, and particle emissions were obtained by increasing the disc surface hardness. Additionally, the effects of disc surface hardness on the tribology performance and particle emissions are more pronounced for the semi-metallic and low-metallic brake materials than non-asbestos organic brake materials.