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

A model friction material was formulated with a cashew-modified phenol ic resin, short carbon fiber, phenolic particles, barytes and steel fi ber. The friction, wear and fade characteristics of this material were determined using a Chase friction material testing machine. The coeff icient of friction was found to vary between 0.2 and 0.5 with lower va lues associated with higher loads, speeds and drum temperatures and vi ce versa. Conditioning the specimens with several fade-recovery test c ycles resulted in steady friction during subsequent fade tests followe d by excellent recovery characteristics. The specific wear rate per un it load and sliding distance decreased with increasing loads, but incr eased with increasing drum speeds and temperatures due to thermal degr adation of the resin. The carbon-fiber-reinforced friction material sh owed lower specific wear rates than that of a milled glass-fiber-based friction material at low speeds and temperatures over a wide load ran ge.