The evolution history of automobile brake friction materials The development of automobile brake friction materials is divided into the following three stages: the first stage is the stage of the development of brake materials, which is mainly drum brakes; the second stage is the stage of rapid development of brake materials , Many new materials began to be born. This stage is the brake that mainly uses disc brakes; the third stage is the stage when the brake material develops to its peak, and this stage is the brake that mainly uses disc brakes, a variety of new materials are emerging in an endless stream. Technical standard and composition of automobile brake friction material 1.1 Technical Standards First, proper and smooth anti-friction properties. Appropriate and stable anti-friction properties can ensure "soft" friction. Second, excellent mechanical strength and physical properties. Mechanical strength can ensure that the material is not prone to breakage and avoid the serious consequences that may result from braking failure. Third, low braking noise. In order to protect the environment, the vehicle braking noise should not exceed 85dB. Fourth, reduce the wear on the chassis. The braking process should avoid wear and scratches on the friction disc. 1.2 Composition of brake friction materials First, organic binders. Phenolic resins and modified phenolic resins are two very important types. Second, fiber reinforced materials. Metal fibers replace asbestos as the main material, and lubricating components, fillers and friction modifiers are embedded in the metal and sintered to form sintered brake friction materials. Third, the filler. The related reagents formulated and the reagents regulating the friction properties make up this part. 1.3 Classification of Automotive Brake Materials (1) Asbestos brake friction material: good comprehensive friction performance, high melting point, high mechanical strength and strong adsorption force make asbestos fibers stand out. Since 1970, its development has been hindered by poor heat transfer performance and increased material wear. (2) Metal-based non-asbestos brake friction material: The brake friction material made of fire-calcined metal and finely divided metal is composed of this material. The calcined iron and copper and other metals are difficult to separate and easy to fuse. disuse. On the contrary, the finely divided metal brake friction material composed of copper and iron is not widely used due to its high cost, excessive production steps, and easy noise generation. (3) Semi-metal-based non-asbestos brake friction material: various non-metal fibers and metal fibers greatly improve the friction resistance of brake materials, so they are widely used. However, its steel fibers are easy to rust and lead to serious wear and other problems are still the focus of research by experts from all walks of life. (4) Non-metallic-based non-asbestos brake friction materials: various carbon/carbon friction materials win with their excellent friction ability and high bending resistance. But the high price also limits its promotion. Internationally, my country is in a leading position in the preparation of various carbon/carbon brake materials. (5) Various brake friction materials in the field of engineering ceramics: the characteristics of low wear rate, high heat capacity and anti-friction have led many researchers to use this inorganic non-metallic material to develop brake materials, and progress has been made. However, its disadvantage of being easily broken also limits its application space. Development trend of domestic automotive brake materials At present, the material composition design is still the starting point for the research of automobile brake friction materials. Although the methods vary from country to country, improving the performance of new friction materials and meeting the needs of environmental protection are still the ultimate goal. Under the guidance of sustainable development theory, the development focus of brake friction materials has been developing towards the trend of low noise and no pollution. This development is also in line with the current trend and social requirements. With the rapid development of manufacturing technology, The development of automobile brake materials will also show diversified characteristics. Diversified brake materials can be selected for vehicles with different climates, regions and functions. In this way, the braking performance of the car can play a high-performance and high-efficiency braking effect. Under normal circumstances, the advancement of science and technology is the guarantee for the optimization and diversification of brake friction materials, and can also meet the needs of the automotive industry. The shortcomings of a single reinforced fiber are unavoidable, the smooth surface of glass fiber is difficult to infiltrate with resin; steel material is difficult to avoid the problem of rust; carbon material is complicated in process, high in price, and difficult to promote. Therefore, hybrid fibers have become the research focus of various countries. Steel fibers, carbon fibers, carbon fibers and copper fibers can draw on various advantages, give full play to the advantages of fibers, reduce costs, and improve performance. In order to solve the problem of phenolic resin under the action of high temperature, many enterprises and scientific research institutions use other more excellent raw materials such as butylbenzene to make phenolic resin different from the previous through their active research and development. Therefore, such an updated phenolic resin Resin is also a new direction for the research and development of automotive brake friction materials. Summarize To sum up, the development of automobile brake friction materials emerges one after another in the development of automobiles, which has played a driving role in improving the performance of automobile braking. With the development of new technologies and new materials, the development trend of automobile brake friction materials will show diversification and low consumption, and the improvement of material technology will also greatly promote the development of automobile brake friction materials.