How are the materials of brake pads classified?

Summary:The materials of brake pads are classified as follows: 1. Asbestos material: low cost, light weight, widely used in cons...
The materials of brake pads are classified as follows:
1. Asbestos material: low cost, light weight, widely used in construction vehicles on trucks. However, the brake pads made of asbestos are prone to generate serious dust during driving and pollute the environment. So far, our country has now completely banned the production of such brake pads.
2. Semi-metal material: The brake pads of all car series have this formula when they leave the factory. Of course, this is the cheapest. The friction coefficient of this kind of brake pads is low. Generally, the friction coefficient is 0.38, and the service life is short. The friction coefficient of the brake pads is very high, of course, this is also a disadvantage and prone to noise. Generally, the use of such brake pads on Japanese cars is prone to noise. It is also closely related to the brake disc.
3. Metal material: Metal material includes iron and copper. There is a commonly known as wear-resistant iron. This kind of metal plate is relatively black, you can't see any points, and there is another kind of copper powder, you can see some metal blocks or small particles of brass or red copper on the surface of the brake pad. In the process of using this kind of iron brake pads, the brakes are lightly stepped on, and the car is easy to stop. The harder it is to step on, it's easy to get caught. There is also a copper powder material, which is relatively sticky. As soon as our feet are placed on the brake pedal, there will be a feeling that the vehicle is about to stop. It is also easier to use, but this material has a short service life. Not wear-resistant.
4. Ceramic brake pads: moderate density, high temperature resistance, corrosion resistance, the noise will be much lower than that of metal materials, and the feature is that it does not fall off dust. Some cars on the market have very dirty wheels after running for a while, and some are very black powder. It's the kind of sheet metal that's ground down. The current ceramic piece has almost no ash. This wheel looks very clean and has a long service life. The ceramic pieces are of excellent workmanship and can be seen grey and whitish to the naked eye. High-end models are widely used. Nowadays, many cars still use metal plates. Taxi using the original brake pads generally need to be replaced with new brake pads for 20,000 to 30,000 kilometers. After replacing with our ceramic plates, it can be used for about 60,000 kilometers. Real ceramic brake pads also contain aramid fibers, which are far superior to the above formula brake pads in terms of service life and brake pad performance.
5. High carbon (titanium) fiber: It is the carbon fiber brake pads used in our high-end vehicles of Meijiarun, which are relatively rare in the market now. Carbon (titanium) fibers are an upgraded version of ceramic sheets. Light weight, high strength, small thermal expansion coefficient, (the probability of deformation is relatively small), good thermal conductivity, heat resistance and other characteristics. The carbon fiber curve has good stability, the friction surface has a small thermal shock, and the wear resistance is more than 1.5 times that of ordinary ceramic sheets. Carbon fiber brake pads have high temperature resistance, the temperature can reach 600 degrees, good heat dissipation and high hardness. Of course, it is also very expensive. Carbon fiber friction materials are the best performance among various types of friction materials. Carbon fiber friction pads have high absorption power per unit area and light specific gravity, and are especially suitable for the production of aircraft brake pads. They are also used in the brake pads of some high-end sports car-level racing cars abroad.