Fabrication and characterization of SiC_f/SiC composite by CVI using the whiskering process

The chemical vapor infiltration (CVI) process is an effective method for fabricating SiC fiber-reinforced SiC matrix composites but it is slow with an inherent drawback of substantial residual porosity. To obtain the dense SiC_f/SiC composite by the CVI process, in situ whisker growing and matrix filling (called whiskering process) was applied. The process was designed to reduce the canning effect during the CVI process and may serve to divide the large natural pores between fibers or bundles by the grown whisker and then fill the matrix inside the modified pore structure. This process was performed using MTS (CH₃SiCl₃) as a source gas and H₂ or N₂ as a diluent and the amounts of the whiskers into the matrix phases were changed by controlling the whiskering cycles. The infiltration effects, that is, increasing of the density of the SiC_f/SiC composite were investigated. And the improved SiC_f/SiC composites were fabricated using this process.