Development Of Multi-fibers Reinforced Friction Materials Of Automotive Brake

With development of modern automotive industry and the enhancement of conscious on environment protection, the performance of the friction materials was required higher because the friction material in an automotive brake system plays a key role for effective and safe bake performance. Because the asbestos is carcinogenic, scholars all over the world started to research on the non-asbestos friction materials and make a great progress. But compared to foreign country, there is some distance. As China's entrance in WTO, friction materials have to face with rigorous challenge and must accelerate the step on develop automotive friction materials especially on high performance friction material. The mechanism of friction and wear and the surface morphology of the resulted friction material obtained at different temperatures were analyzed by Scanning Electron Microscope (SEM).Based on consulting and analyzing lots of internal and overseas documents about friction materials, this paper study a kind of high performance friction material, this friction material contains cashew nut shell liquid modified resin, reinforcing fibers: Kevlar pulp,glass fiber,potassium titanate whiskers,grammite, and fillers: Al₂O₃,Fe₂O₃,vermiculites,cashew dust,barium sulphate etc. Utilizing the hybrid reinforcing manner of Kevlar pulp,glass fiber,potassium titanate whiskers and grammite. Designing the formula by orthogonal test and analyzing the influence of content on the frictional property, and making variance analysis and formula optimization based on the constant speed test results. The important results from this study are summarized as follows: formula optimization: Kevlar pulp 3%, glass fiber12%, potassium titanate 10%, grammite 12%, Vermiculite 6%, graphite 4%, coke 8%, friction powder 6%, the other 50%; There are obvious hybrid effect between the Kevlar pulp and glass fiber, glass fiber and potassium titanate whiskers, Kevlar pulp and potassium titanate whiskers, which is important to the friction and wear. Phenolic resin was agglomerant in friction material. Fade which caused by pyrolysis of modified phenolic resin at high temperatures, can be reduced by decreasing the content of phenolic resin properly. Vermiculite has a marked effect on friction coefficient and wear rate in high temperature. Vermiculite not only can decrease the product's density and hardness, but also can increase the friction stability. In high temperature rang, the wear mechanism of friction material mainly was cohesiveness friction and fatigue abrasion. The transfer film plays a key role for performance of friction and wear.Experiment test result shows that formula material with a relatively suitable friction coefficient, good coefficient,good fade resistance and recovery as well as low wear ratio can meet the need of the break property of the Automotive. This kind of brake material formula can be achieved for heavy automobile.