
Friction plates are primarily composed of rubber, cork, and fiber materials, and do not contain asbestos. Below is an introduction to the types of friction plates: 1. Paper-based friction materials: Mainly made from imported carbon fiber, aramid fiber, and imported resin through compounding. Suitable for racing cars and high-displacement motorcycles, they feature extremely stable friction coefficients, minimal high-temperature friction coefficient degradation, excellent resistance to burning, and superior thermal recovery performance (the friction coefficient quickly returns to its original state after the clutch cools down following high-temperature slippage). 2. Resin-based friction materials: Primarily composed of reinforcing fibers, friction powder, and resin through compounding. They exhibit high hardness, wear resistance, and can withstand temperatures up to 350 degrees Celsius. Mainly used in various mechanical clutches and motor reducers, their performance is comparable to that of imported products from Taiwan. 3. Carbon fiber friction materials: Mainly made from carbon fiber, imported rubber, and imported cork as the primary raw materials, processed with high-quality techniques. They can withstand temperatures up to 350 degrees Celsius, endure wear over 25,000 kilometers, produce no noise, resist slipping and burning, making them premium products among friction materials. 4. Semi-metallic friction materials: Mainly composed of rubber, friction powder, fiber, and metal fiber through compounding. The products feature wear resistance, ultra-high hardness, and high friction coefficients, making them the best choice for mechanical clutches and motor braking systems.

I've replaced quite a few brake pads during repairs. Friction materials are essentially composite materials pressed from several components. The most common formulation uses resin as a binder mixed with metal powders for enhanced wear resistance—copper and iron powders are typical, while premium versions may incorporate ceramic particles. The middle fiber layer is crucial—asbestos has been phased out and replaced with aramid fibers that offer superior heat resistance and toughness. I've seen cases where aggressive driving caused standard friction materials to turn blue-purple from phenolic resin overheating. Nowadays, copper-free formulations are trending in EVs for environmental reasons, though they tend to deliver a firmer pedal feel in practice.

From a professional perspective, the material composition of friction linings is quite ingenious. The base materials fall into three main categories: the binder often uses modified phenolic resin, wear-resistant fillers typically employ copper/steel fibers or alumina ceramic particles, while the reinforcement skeleton has evolved from asbestos to aramid or fiberglass. Designers must balance friction coefficient and thermal fade characteristics—racing pads contain more metal, heating up quickly but prone to squealing; family car pads favor ceramic formulations, offering quiet operation but poorer low-temperature performance. Recent tests revealed that copper-based linings provide the shortest braking distance below 200°C, while NAO formulations demonstrate better stability after high-temperature mountain driving. Currently, laser-drilled slots for heat dissipation are trending, though the core materials remain unchanged.

When modifying brakes myself, I researched that civilian friction pad materials are divided into three categories: semi-metallic/low-metallic/ceramic. Semi-metallic pads are the cheapest, using steel wool mixed with resin, but produce heavy black dust; low-metallic pads add copper particles for better braking linearity; ceramic pads actually also contain metal, being ceramic fibers mixed with copper wires, with the biggest advantage being quiet operation and non-damaging to rotors. A veteran mechanic told me that OEM pads use specific ratio formulations, and even if aftermarket performance pads have identical parameters, differences in heat dissipation and thermal expansion coefficients can still damage the calipers.

Once in the materials lab, I was amazed by the microstructure of friction pads. The resin matrix resembles concrete, with metal fibers embedded like steel bars, and graphite acts as a lubricant in the gaps. The formulator mentioned three key parameters: a μ value between 0.35-0.45 is safest, thermal decay must remain effective up to 650°C, and shear strength should withstand 70 MPa pressure. The latest advancement uses aramid pulp to replace asbestos, reducing weight by 15% at the same thickness. However, a reminder for car enthusiasts: drive gently for the first 300 km after installing new pads to allow the resin to fully thermally cure.


