Effects of molding pressure on the properties of 2D-woven Cf/SiC composites

Using PCS and SiC micropwder as raw materials, 2D-Carbon fiber cloth as reinforcer, 2D-Cf/SiC composites were prepared, adopting precursor transformation process. The effects of molding pressures on the mechanical properties of 2D-C-f/SiC composites were investigated. The results show that the mechanical properties cannot be obviously improved with the increase of molding pressure. The main reason could be ascribed to that the SiC micropowder damages the carbon fiber more and more seriously on the one hand, and on the other hand the fiber volume fraction is increased with the increase of molding pressure, resulting in a unnoticeable influence of the molding pressure on the mechanical properties of the composite. The anti-oxidation properties of the composites fabricated under molding pressure are better than that of composite under pressureless. The primary reason is that flaws appear more easily in the matrix of composites fabricated with 0 MPa, resulting in more serious damnification on properties of composites in oxidation atmosphere at high temperature.