Microstructure and mechanical properties of 2D laminated C/C-SiC composites prepared by low-temperature reactive melt infiltration with silicon alloy

This study presents a cost-effective and time-efficient method for preparing C/C-SiC composites using low-temperature RMI with Si-33Ni and Si-14Ti alloys, addressing the high reactivity of pure Si. Carbon fiber plain cloth was surface treated, impregnated with phenolic resin, laminated with hot pressing, and carbonized to form C/C composites, which were then infiltrated with Si-Ni and Si-Ti alloys at 1390°C to 1550°C. The results show that the C/C-SiC composites prepared at 1390°C using Si-Ni alloy and at 1550°C using Si-Ti alloy exhibit superior mechanical properties, with flexural strengths of 230 MPa and 221 MPa, and fracture toughnesses of 5.12 MPa·m^1/2 and 4.89 MPa·m^1/2, respectively—surpassing those prepared with pure Si. Because of the brittle Si were replaced by related alloy phase and few damages to fibers during RMI. These findings provide insights into the low-temperature RMI process and pave the way for developing next-generation lightweight, high-strength composite materials.