EFFECT OF BRAKING SPEED ON FRICTION AND WEAR BEHAVIORS OF C/C-SiC COMPOSITES

C/C-SiC composites were fabricated by the reaction melt infiltration method. Braking tests were carried out on an MM-1000 test machine simulating airplane braking. The friction and wear behaviors of C/C-SiC composites at different braking speeds were investigated. The experimental results show that the coefficient of friction increases to the maximum value of 0.52 at 10 m/s and then falls afterwards with the increase of braking speed. The wear rate remains low at low braking speeds and increases line-arly with the increase of the braking speed, which demonstrates that the C/C-SiC composites have excellent wear resistance in com-parison with C/C composites. Due to the high braking energy, ploughs appear on the friction surface and a large amount of spherical wear debris forms; therefore, the coefficient of friction decreases sharply when the braking speed exceeds 20 m/s.