When braking, the generated waer debris is responsible for the formulation of a so-called third body layer. Depending on the initiation, growth and degradiation of this layer the actual friction coefficient and wear are generated.
Mineral fibres play an essential role
To maintain the surface of the friction material effectively attached to the brake pad, anchoring points are needed. Mineral fibres can play a role here as they function as a primary plateau as shown above. During sliding friction, wear debris can agglomerate around the mineral fibres and start the formation of a secondary plateau. Anchoring points contribute considerably to improved friction stability and wear resistance.
The presence of fibrous anchoring points is proven to be essential in obtaining optimal friction performance aspects, particularly when talking about copper free materials. In current copper-free formulations, the secondary pleateau cannot exist without these structural components in the friction material.
Elements in a third body layer
The third body layer consists of a sei-continuous layer formed by primary and secondary plateaus and its composition depends on many factors. It is dependent on the components used in the friction material, the quality and composition of the disc, environmental conditions and the braking system in general. Plateaus are usually made up of iron oxide, copper, carbon, silicon and calcium elements.