ZHANG Jiqin ¹, JIAN Ke ², WANG Hao ²

(1.China International Engineering Consulting Corporation, Bejing 100048, China; 2. Science and Technology on Advanced Ceramic Fibers &Composites Laboratory, National University of Defense Technology, Changsha 410073, Hunan, China )

Abstract: The thermal expansion of C_f /SiC composites fabricated by precursor infi ltration and pyrolysis was studied. The results showed that the coeffi cient of thermal expansion of C_f/SiC composites was related to the microstructure of the composites. Because the crystallization of SiC matrix derived from precursor pyrolysis was low, the coeffi cient of thermal expansion (CTE) of C_f/SiC composites was low. At the same time, because the axial CTE of carbon fi ber was lower than that of SiC matrix, along x dimension, the CTE of 3D C_f/SiC composites was lower than that of 2D C_f/SiC composites, and the CTE of 2D C_f/SiC composites along x dimension was lower than along z dimension.

Key words: C_f/SiC composites; precursor infi ltration and pyrolysis; coeffi cient of thermal expansion