LOAD, SPEED AND TEMPERATURE SENSITIVITIES OF A CARBON-FIBER-REINFORCED PHENOLIC FRICTION MATERIAL

A model friction material was formulated with a cashew-modified phenolic resin, short carbon fiber, phenolic particles, barytes and steel fiber. The friction, wear and fade characteristics of this material were determined using a Chase friction material testing machine. The coefficient of friction was found to vary between 0.2 and 0.5 with lower values associated with higher loads, speeds and drum temperatures and vice versa. Conditioning the specimens with several fade-recovery test cycles resulted in steady friction during subsequent fade tests followed by excellent recovery characteristics. The specific wear rate per unit load and sliding distance decreased with increasing loads, but increased with increasing drum speeds and temperatures due to thermal degradation of the resin. The carbon-fiber-reinforced friction material showed lower specific wear rates than that of a milled glass-fiber-based friction material at low speeds and temperatures over a wide load range.