A SiCnw/ZrC porous ceramic fabricated via a direct foaming method with enhanced load-bearing, thermal insulation, and electromagnetic wave absorption properties

To address the increasing demands for multifunctionality in thermal insulation, electromagnetic wave absorption, and load-bearing capabilities, a silicon carbide nanowire (SiC nw )/zirconium carbide (ZrC) porous ceramic was synthesized by a liquid-phase precursor foaming method with a density of 0.54 g/cm 3 and a porosity of 88.3%. The SiC nw was in-situ grown in the sintering process, which is interwoven within the ZrC porous ceramic, forming a three-dimensional network structure. The SiC nw /ZrC porous ceramic exhibits outstanding electromagnetic wave absorption (the minimum reflection loss of −66.25 dB, the maximum effective absorption bandwidth of 5.4 GHz), low thermal conductivity (0.218 W·m −1 ·K −1 ), and high compression strength (45.9 MPa). In-situ grown SiC nanowires not only enhance the polarization loss and interface loss of porous ceramics, but also act as reinforcing phases to bear and transfer loads, achieving a synergistic improvement in load-bearing and wave-absorbing performance. In addition, the in-situ growth of SiC nw effectively improves the porosity and pore size distribution of porous ceramics, leading to an enhancement in thermal insulation performance. This research provides a new idea for the design of multifunctional integrated materials with the functions of load-bearing, thermal insulation and electromagnetic wave absorption in extreme aerospace environments.