Temperature And Pressure - In Situ Reaction Method, C / C - Sic Brake Materials Friction And Wear Properties

At the end of 20 century, the C/C-SiC composites had been applied to the friction field as a new kind of braking material, which has the advantages of low density, perfect anti-corrupt, excellent oxidation resistance and good friction properties, and it also has the broad application prospect. In this paper, combined with the former research result, warm compacted-in suit reaction process has been used to manufacture the C/C-SiC composites. The influences of different treatment processing, different component and short carbon fiber on the friction and wear capacity have been studied. The friction surface and wear debris are analyzed by SEM and X-Ray. The results show that:(1) In the short carbon fiber enforced composites, the fiber distribution is an important factor which influences the strength of composites. Fiber dispersal can exert the enhancement function of carbon fiber, increase the strength of material, thus improve the friction properties. Resin impregnation can increase the densification ratio of material, helps to form friction film, improve friction coefficient and decrease the wear. The resin helps to form friction film, but the wear of material increase dues to the seriously wear of thermal-oxidation. After carbonization, the resin is transformed into the resin carbon, which increases the friction coefficient acts as wear debris particles, and decreases the wear rate of material at the same time.(2) In the C/C-SiC composites, there are two aspects of influences of SiC content on the friction properties of C/C-SiC braking material. One is that the SiC content can increase the rigidity of material, and improve the friction properties; on the other hand, the too high content of SiC can cause the increase of brittleness and the decrease of toughness of material, thereby the surface resistance of wear properties decreases, and the wear of material is increased. So there is a best content of SiC to the friction properties. The kinds of graphite influence the friction properties of C/C-SiC braking material, and the material which is made by the grain graphite has the best friction capacity, but the material made by squama graphite has the relatively bigger wear. The exist of moderate content of purity Si can decrease open porosity rate of C/C-SiC composites availably, increase the thermal conductivity and decrease the wear rate of material.(3) The friction and wear behaviors of C/C-SiC composites are significantly influenced by carbon length and carbon fiber content. With the increase of carbon volume content, the friction coefficient first rise and then fall, but the wear rate is opposite. The material manufactured by longer carbon fiber has the better friction and wear properties.(4) Based on the observation and analysis of C/C-SiC composites' surface friction morpha, the surface has been measured off into three layers from outer to inner according to the surface temperature: high temperature friction layer, crack layer and body. The friction and wear behaviors of C/C-SiC composites are the action of furrow and adhesive synchronously, and the particle wear is taken as the main form. The increase of rigidity and brake toughness of material can decrease the wear rate of C/C-SiC composites effectively.