Fabrication and mechanical properties of 2D Cf/SiC composites by joint process of vacuum bag molding, PIP, and RMI

Abstract

The structural integrity of continuous carbon fiber-reinforced silicon carbide (C_f/SiC) composites is often compromised by carbon fiber damage during high-temperature sintering, nonuniform fiber distribution, and the brittleness of the ceramic matrix, which limits their broader application. This study reported an innovative approach of vacuum bagging combined with thermal press curing, followed by precursor infiltration and pyrolysis (PIP) and reaction melt infiltration (RMI), densification to fabricate a C_f/SiC composite with remarkable properties. The pyrolytic carbon (PyC)/boron nitride (BN) double interface layers were deposited to the C_f via chemical vapor deposition (CVD). Results revealed that vacuum bagging combined with thermal press curing effectively eliminated bond-line defects, while the PyC/BN interface layer further improved the toughening of C_f. The combination of vacuum bagging and thermal press curing showed optimal strength of 330 ± 30 MPa and 7.4 ± 0.5 MPa m^1/2, representing increases of 50% and 47%, respectively. The failure mechanisms responsible for the mechanical behavior are gained through macro and microanalysis. This work provides a high-performance, economical, and convenient process for enhancing the mechanical performance of C_f/SiC composites, providing valuable insights for the development of ceramic matrix composites.