Preparation and characterization of carbon/carbon aircraft brake materials with long service life and good frictional properties

A320 series aircraft carbon/carbon brake materials were prepared by processing a needle-punched carbon fiber preform with quasi-three-dimensional integrity. The preform was first impregnated with a resin and heated to 800℃ to convert the resin to carbon. This was followed by chemical vapor infiltration (CVD) using propylene as the source gas and a radial thermal gradient ("external heating, internal cooling" or "internal heating, external cooling"). For the CVD process the performs were separated by graphite pads to allow free flow of propylene along the channels thus formed. The final brake discs were obtained by a further hightemperature treatment from 1600-2400℃. These carbon brake discs were compared with the advanced discs made abroad in terms of ground test and service performance. The two kinds of carbon brakes have the same friction coefficients under the designed landing energy and overload energy braking condition for A320 airplanes. Especially, under the aborted take-off condition, the friction coefficient of the domestically developed carbon brake disc was 21-48% higher and the static friction coefficient was 28% higher than that of the ones provided by the aircraft manufacturer. The average brake service life exceeds 2700 landings, 24% times larger than the original ones.