Tribological properties of 3D needled C/SiC brake materials

3D needled C/SiC brake materials were prepared by a combination of chemical vapor infiltration (CVI)and reactive melt infilt ration (RMI). The tribological properties of the as-manufactured C/SiC composites were systematically studied by MM-1000 tribological tester. The microst ructure characteristics of the f riction surface and wear debris were observed by optical microscope and SEM, respectively. The results indicate that at the same braking speed the dry friction coefficient falls down with the increase of braking pressure; and at the same braking pressure the dry friction coefficient firstly increases and then decreases with the increase of braking speed. The dry friction coefficient falls down obviously as the initial braking temperature rising. The wet friction coefficient fades down a little (about 8 % of the dry f riction coefficient) and recovers quickly. The static f riction coefficient is about 0.56～0.61. The wear rate arises with the increase of braking speed at the same braking pressure. When the braking speed is more than 20 m/s, the wear rate increases obviously with the increase of braking pressure.