Effects of joint processes of CLVD and PIP on the microstructure and mechanical properties of C/C-ZrC composites

Abstract Chemical liquid-vapor deposition (CLVD) has obtained increasing interest in the rapid fabrication of composites. But according to the characteristics of CLVD process, it is difficult to fully and homogeneously densify the composites, thus CLVD combined with PIP process was proposed to meet these shortcomings. In this paper, joint processes of CLVD and PIP were used to prepare C/C-ZrC composites. Meanwhile, the influence of joint processes on the microstructure and mechanical properties were investigated. The results showed that, due to the high deposition efficiency and co-deposition in CLVD session, the preparation periods of joint processes has been greatly reduced, which were only 40 h. During joint processes, small pores in bundles were preferentially filled in CLVD process, but large pores between bundles and layers were preferentially deposited in PIP process, thus homogeneity of composites were remarkably improved. A schematic model of joint processes was also proposed to analyze densification behavior. Additionally, the resulted composites exhibited a non-brittle fracture mode with high flexural strength, which was attributed to the high density, homogeneous structure and proper bonding of fiber-matrix interface.