Research And Test Of The Key Character Of Automotive Bake Friction Materials

This paper is mainly about the test and research of friction materials' character of heat-fading and wear-loss. Focusing on the improvement of friction materials' component and the application of cooling-structure for it, we attempt to improve materials' ability of temperature resistance and reduce the surface temperature of friction materials by making use of cooling-structure to improve the stability of brake.The key characters of a few typical friction materials were tested through the character test bed of motorcycle brake. The test items contain checking examination before wear-in, wear-in, the braking performance after wear-in, heat-fading, heat-resuming, final performance, water-fading and water- resuming etc. The friction surfaces have been analysed by scanning electron microscopy(SEM), after the two types of friction materials were frictionated with their counterparts. Surface films of oxidation, lubricating, air cushion and transfer are discovered. Powder metal brake lining has little fading, and heat fading for this brake lining can be controlled very little. Nonmetal brake lining contains large amount of phenolic resin which can be easy to be decomposed into liquid or gas. The effect of lubricating is so evident that the heat fading of this lining is serious.To Powder metal friction materials for heavy truck, for its good heat-transmit character, cooling-structure is added to cool the surface temperature of it to reduce the fading. The cooling system is made up of brake lining, temperature sensor, electric pump and controlling circuitry etc. Brake lining' temperature is monitored by temperature sensor, and when the temperature is over or under the limited value, controlling circuitry will have the pump work or not to make the cooling system open or close.The structure of common brake is improved to increase the brake moment. That will reduce brake time and add the cooling interval. So it does favor to the heat-resuming after heat-fading and eases up the brake's heat-fading.Friction material is a key factor to affect the driving-safety, this research can offer reference on how to choose reasonable materials component and improve the structure of braking lining and plate.