Effects of Carbon Fiber Dispersion on Bending Property of Cf/SiC Brake Materials

Abstract

With increasing of the speed of the train, the requirement of the performance of the braking friction materials is more and more higher. It is urgent to find new braking materials to satisfy the rigorous using environment. Cf/SiC has the broad application prospects when it is used as a new kind of braking material. On this article, in order to shorten preparation cycle and reduced production costs, short carbon fiber is substituted continuous carbon fiber felt. Cf/SiC brake materials were prepared by the way of molding compression-pressureless sintering with resin binder. The effect of short carbon fiber dispersion on bending properties of brake materials was researched. The experimental results show that the bending strength of Cf/SiC brake materials, which manufactured by dispersing short carbon fibers, is higher than the composites manufactured by using fiber bundle. When the distribution of carbon fiber in composites is in single fiber state, the interfacial strength between carbon fibers and matrix were increased. At the experimental condition, compared to the sample with fiber bundle, the bending strength of the specimen with dispersed fiber is increased 40.79%. The toughening mechanism of carbon fiber debonding and fiber pull were generated in the process of bending fracture. The fracture model of composites is pseudo-ductile type.