Brake pads are generally made of the following materials:
1. Binder
It is an important part of brake pads, which can bond various friction materials and filler materials together. The common one is phenolic resin, which has good thermal stability and mechanical properties. Phenolic resin can maintain a certain degree of strength at high temperatures, ensuring the structural integrity of the brake pad. It can mix other materials evenly during the manufacturing process of brake pads, so that the brake pads have stable friction performance in the braking process.
2. Friction materials
Asbestos fibers: Asbestos has good heat resistance and friction properties. However, since asbestos fiber is a carcinogen, its use is strictly limited or banned in many countries and regions.
Semi-metallic materials: Semi-metallic brake pads mainly contain metal fibers, such as steel fibers and copper fibers. These metallic fibers can enhance the strength and wear resistance of brake pads. Among them, steel fibers can withstand higher temperatures and pressures, and are more commonly used in frequent braking situations. Copper fibers, on the other hand, help to improve the thermal conductivity of the brake pads so that heat can be dissipated more quickly, reducing thermal degradation of the brake system.
Ceramic material: ceramic brake pad is a kind of high-performance brake pad. It is mainly composed of ceramic fiber, filler, and binder. Ceramic brake pads have low heat degradation and can still maintain good braking performance at high temperatures. And it produces less dust, which is less polluting to the environment and the wheels. Its braking process is relatively quiet without sharp noise, so it is widely used in many medium and high-grade automobiles.
Organic Material (Non-Asbestos Organic - NAO): These brake pads are reinforced with organic fibers such as glass fiber, aramid fiber, etc., with other organic friction modifiers and binders. It provides good braking performance and is less abrasive to the brake disk. Meanwhile, it can also have a good initial braking effect in a low-temperature environment, so it is used more in some common family cars.
3. Filler materials
Friction modifiers: e.g., graphite and molybdenum disulfide. Graphite can reduce the coefficient of friction between the brake pads and brake discs, making the braking process smoother, and also has a certain lubricating effect, reducing the generation of noise. Molybdenum disulfide is also a good lubricant, which can maintain stable lubrication performance at high temperature and high pressure, effectively preventing the biting phenomenon between brake pads and brake discs.
Other filler materials: They also include some mineral powders, such as barite and mica. These materials can adjust the density, hardness, and other physical properties of brake pads to meet different braking needs. At the same time, they also help to improve the wear resistance and anti-abrasion ability of brake pads.
