Investigating the impact of the porous structure of needle-punched preform-based carbon-carbon composites on the completeness of liquid silicon infiltration

Currently, siliconized carbon-carbon composites (C/C composites) hold a significant position among materials used in nonferrous metallurgy. The process of Liquid Silicon Infiltration (LSI) for porous C/C composites is strongly inf luenced by their microstructural characteristics. Studying the effect of the porous structure of various C/C composites on the completeness of silicon infiltration can enable the regulation of the phase composition of siliconized materials over a wide range, as well as the physical, mechanical, and thermophysical properties of C/C–SiC composites. This paper presents the results of analyzing the porous structure and strength characteristics of C/C composites based on needle-punched preforms with different types of carbon matrices (pyrocarbon, natural and synthetic pitch coke, and phenol-formaldehyde resin coke) and the C/C–SiC composites derived from them. Due to the specific features of carbon matrix formation from liquid or gas phases, differences in pore size distribution were observed. A carbon matrix formed by the gas-phase method exhibits fewer nanoscale pores compared to one formed by the liquid-phase method. The inf luence of the pore structure and the nature of the matrix carbon in various needle-punched preforms on the degree of saturation during LSI, infiltration depth, and mechanical properties was determined.