The Effect Of Matrix And Reinforcement Fiber On The Friction And Wear Properties Of The Brake Couple Of Gray Iron And Resin-based Composite

With the developments of automotive and train, in-depth study of their braking performances is more practical significance which was important for traffic safety. As the continuous improvement of train speed and load increase, the braking system and materials were required higher performances. The resin matrix composite has been considered as one of the key components for all performances of friction materials. This is because it not only just cements the fiber and inorganic filler, transmits and equalizes load effectively, but also plays a crucial role in improving heat resistance, wear resistance and mechanical properties of the friction materials. In the preparation of resin matrix composite, materials selection and proportion were variety. Different condition of use has some influence to choice of resin matrix, reinforced fiber and filling element, components and fabrication technology. The correct choice of resin matrix composite formula, reasonable structure designed to achieve the best combination of results is very important.The effect of the resin matrix, reinforced fiber to the friction and wear properties of resin matrix composite was study in this paper. The purpose is to explore the optimum formula of resin matrix composite for gray cast iron counter. All of the samples were fabricated via a two-step pressing process. Gray cast iron counter rings and an MM1000 friction material testing machine were employed for friction tests.The resin matrix research shows that, the boron\melamine-cashew modified phenolic resin (FBY resin) has excellent thermal property. The friction material with FBY resin has low hardness and wear, stable friction coefficient. The FBY resin is suitable as the resin matrix for friction materials. Friction material with chemical solution method of the modified nitrle-butadiene rubber (NBR) has better friction and wear properties, and the modified NBR witch BMI modifying level of 6% has the best friction and wear properties.The effect of four different enhanced fiber system (steel, brass, copper and steel/copper ) on friction and wear properties of the resin matrix friction material were study. The results show that the steel fiber reinforced friction material has a higher hardness than that one witch was reinforced with copper fiber because copper fiber deformation easier. Copper fiber reinforced friction material with the highest coefficient of friction and wear, friction material brass fiber reinforced friction coefficient and wear the smallest, steel fiber reinforced friction material friction and wear between the former two. Steel fiber / copper fiber hybrid enhanced friction materials has good friction and wear properties. Copper fiber reinforced when the friction material brake torque curve with greater volatility, steel fiber and steel fiber / copper fiber hybrid enhanced friction materials torque curve flattening, no greater volatility. Comprehensive comparison, steel fiber / copper fiber hybrid enhanced friction material has better performances.Slenderness ratio of steel fiber has grate effects on friction and wear properties of friction material. In this paper, steel fiber was be made of grade, friction material with each grade was be prepared and their performances were compared. This work investigated the effect of steel fiber's slenderness ratio on the friction characteristics of polymeric matrix friction materials. Four different grades of steel fiber were used to produce friction samples. Results showed that the sample with steel fiber which has larger slenderness ratio generated high coefficient of friction and high wear. On the other hand, the sample with smaller slenderness ratio steel fiber showed low impact strength and low coefficient of friction.