Material used to make automobile clutch plates and why

The properties that must consist of the material used for clutch discs are:

• Coefficient of static friction, which describes how well a clutch disc will hold a flywheel under acceleration. If the coefficient is low, the clutch disc will slide against the flywheel, heat up and wear out.
• Dynamic coefficient of friction, which describes how smoothly (or abruptly) a clutch disc will 'grip' a flywheel during engagement. If the coefficient is too high, the clutch will lock up immediately, leading to uncomfortable shifts that make low-speed maneuvering very difficult (a major concern for truck clutch discs).
• Clamping force, which is the amount of force or “weight” that must be applied to a given clutch disc to ensure that it does not slip on the flywheel. The more force applied, the greater the pedal effort on the pedal, the greater the load on the hydraulic system, etc.
• Fading temperature, which is the temperature at which the clutch material begins to lose cohesion. If the temperature is too cold, spending an afternoon towing the family boat (or at the local drag strip) can ruin your clutch disc.

Material used to make automobile clutch plates

There are five different materials used in modern clutch design:

“Organic” clutch material, which is a mixture of fiberglass and other materials (including brass in some cases) molded or woven into a friction pad

Kevlar (and its cousin Twaron), which are synthetic fibers that produce extremely durable (and very forgiving) clutch friction pads

Ceramic clutch material, which is mainly a mixture of silicon dioxide and various metals and additives, sintered or welded onto the clutch disc

Feramic clutch material, which is quite similar to ceramic material, except that it contains a much higher percentage of metal

FeramLiga, which is a new and superior alternative to fermic and ceramic clutch material

Ceramic and feramic clutch disc materials are used in racing or on vehicles with large amounts of torque (commercial trucks, agricultural vehicles, even 3/4 and 1 ton diesel trucks if they have been sufficiently modified). A new material called FeramAlloy will likely replace ceramic and feramic clutch materials as it offers the same key benefits (high coefficient of static friction, high fading temperature) but with a much lower coefficient of dynamic friction that makes shifting much smoother.