Properties of resin-based composite friction materials
With the rapid development of modern transportation industry, people put forward higher requirements for vehicle comfort, stability and safety, requiring friction materials used in brake systems to have stable tribological properties in a large speed and temperature range. The resin matrix composite friction material is one of the most widely used friction materials at present. According to the different functions of each component in the material, the components can be divided into four categories: binder, reinforcement fiber, filler and friction property regulator phenolic resin (PF) has become the main binder in the friction material because of its low cost and good wettability. However, the heat resistance of ordinary PF is poor, and it is easy to decompose into gaseous low-molecular substances at high temperatures, resulting in a sudden drop in the friction coefficient of the material, which leads to the phenomenon of "thermal decay". The methylene in PF is replaced by boron, molybdenum and other elements, which can obviously improve the high temperature friction properties of friction materials. Lin et al. prepared nano-copper modified PF by in-situ generation method, and its initial decomposition temperature was 46℃ higher than that of ordinary PF. Yan Jianwei et al. reinforced the resin-based friction material with fibrous palychite and improved the thermal decay resistance of the friction material. At present, many researchers use modified resins or heat-resistant fillers to improve the thermal decay resistance of friction materials, but the research in this area needs to be further in-depth.
