Shrinkage-controlled hydrothermal carbon: An advanced interphase for achieving synergistic stress dispersion and load transfer in Cf/ZrB2-SiC composites

Controlled shrinkage of hydrothermal carbon coating (HTCC) during its carbonization preparation process offers a novel strategy for optimizing the interfacial properties of fiber-reinforced ceramic matrix materials. In this study, the effect of volumetric shrinkage in monolayer or bilayer HTCC on the interface characteristics and mechanical properties of C f /ZrB 2 -SiC composites is investigated. The bilayer HTCC significantly enhances the crack deflection effect within the interphase compared to the monolayer HTCC. By precisely controlling the shrinkage of the layers of the bilayer HTCC, an innovative C/SiC/C trilayer interphase was synthesized in situ during the polymer infiltration process for preparing the C f /ZrB 2 -SiC composites, which synergistically enhances stress dispersion and load transfer efficiency within the interface. The work of fracture for C f /ZrB 2 -SiC composites modified by the trilayer interphase has been significantly elevated to 2258 J/m 2 , which far exceeds the 129 J/m 2 measured for the composites lacking a HTCC interphase.