Wear mechanisms for asbestos-reinforced automotive friction materials

An asbestos-reinforced automotive friction material was evaluated by dynamometer testing for its wear characteristics at elevated temperatures. Wear rate constants were obtained for different temperatures, and an activation energy was obtained for the high-temperature wear process. It is concluded that the wear is controlled by a pyrolysis mechanism at elevated temperatures (above 450°F drum temperature) and by adhesive and abrasive mechanisms at low temperatures.