Preparation And Property Research Of C/C-SiC Friction Materials

C/C-Si C composite is a new type of friction material,and has a wide application market.This paper combined with the temperature and pressure in situ reaction method and liquid blending method using silicon,temperature and pressure of liquid blending process for preparation of silicon integrated with short cycle,low cost of C/C-SiC friction materials with short fiber reinforced resin matrix C using warm compaction technology for preparation of C/C porous body,using liquid silicone blending method the reaction of the Si C matrix,and then prepared C/C-SiC friction material.In the experiment,carbon fiber distribution,length and carbon fiber volume fraction and liquid silicon fusion temperature were used as single variables to study their effects on material properties,including bending strength,oxidation performance and friction and wear properties.The mechanism of the bending fracture and the friction and wear mechanism of the prepared materials are analyzed.The conclusions are as follows:（1）The properties of C/C-Si C friction materials prepared by molten silicon permeation temperature at 1600 C are excellent,and the bending strength is the greatest.（2）In the experiment,whether the short fiber is dispersed or not has a significant influence on the bending and friction and wear properties of the material.The dispersion treatment of fibers can make the fibers distribute better and evenly in the matrix and combine more interfaces,so as to give full play to the toughening effect of short fibers and improve the properties of materials.（3）The flexural strength and friction and wear properties of C/C-SiC friction materials are also related to the length and volume fraction of carbon fibers.The bending properties and friction and wear properties of materials made of C/C-SiC are best when the fiber length is 10mm and the volume fraction is 15%.（4）The main mechanism of toughening is carbon fiber debonding and fiber pullout during the bending failure of C/C-SiC friction material.The main wear mechanism is abrasive wear and adhesive wear in the process of friction and wear.（5）When C/C-SiC friction material is oxidized at 800 degrees,a small amount of SiO₂will be generated.SiO₂ will adhere to silicon carbide on the surface of a dense protective film to prevent further oxidation of the matrix.If the oxidation time is long enough,the protective film will also be destroyed.