Microstructure and frictional properties of 3D needled C/SiC brake materials modified with graphite

The 3D needled C/SiC brake materials modified with graphite were prepared by a combined process of the chemical vapor infiltration, slurry infiltration and liquid silicon infiltration process. The microstructure and frictional properties of the brake materials were investigated. The density and open porosity of the materials as-received were about (2.1±0.1) g/cm3 and (5±1)%, respectively. The brake materials were composed of 59% C, 39% SiC, and 2% Si (mass fraction). The content of Si in the C/SiC brake materials modified with graphite was far less than that in the C/SiC brake materials without being modified with graphite, and the Si was dispersed. The braking curve of the 3D needled C/SiC modified with graphite was smooth, which can ensure the smooth and comfortable braking. The frictional properties under wet condition of the 3D needled C/SiC modified with graphite showed no fading. And the linear wear rate of the C/SiC modified with graphite was lower than that of the C/SiC unmodified.