Effect of structure integrality of aircraft braking C/C composites on their friction coefficients

The degree of graphitization of C/C composites partly represents their structure integrity since the structure of C/C composites is graphitelike. The mechanism of friction and wear of C/C friction materials was investigated by correlating the degree of graphitization of C/C composites to their braking torque characteristics and runin friction coefficients. It is found that active sites present at edges and corners on the surface of C/C composites increase physi and chemisorption of the materials and decrease friction coefficients in the first several seconds of runin. The oxygen in carbonoxygen complexes within the C/C composites affects the value of the friction coefficient when the temperature of the brake materials is between 400 and 500?℃. These two factors jointly deteriorate the brake performance of C/C composites.