Microstructure, strength and toughness of C/SiC composite modified by PIP-SiC matrix

Abstract

The matrix of fiber bundle composite C/SiC was modified by the combination means of precursor infiltration and pyrolysis (PIP) and chemical vapor infiltration (CVI). The microstructure of SiC matrix fabricated by PIP (PIP-SiC), and the fracture morphologies of the unmodified and modified composites were observed. Meanwhile, the tensile properties of the unmodified and modified composites were tested. The results show that PIP-SiC matrix modification improves the modulus matching between the fiber and matrix of C/SiC composite, and effectively improves the strength, toughness and stability of C/SiC composite. The tensile strength of modified C/SiC composite is slightly higher than that of unmodified C/SiC composite. Furthermore, the Weibull modulus, elongation and fracture work of modified C/SiC composite are 22%, 28% and 20% higher than those of unmodified C/SiC composite, respectively. Meanwhile, the variation coefficient (CV) of tensile strength, elongation and fracture work of modified C/SiC composite is 15%, 12% and 5% lower than that of unmodified C/SiC composite.

Keywords

• c/sic composite
• precursor infiltration and pyrolysis
• matrix modification
• strength and toughness