Lightweight TiC/ZrC Ceramic Foams for Extreme Temperatures: Simultaneous Thermal Insulation, Broadband EM Absorption, and High-Temperature Resilience

Lightweight TiC/ZrC ceramic foams were successfully fabricated using a self-foaming method to address thermal-electromagnetic coupling in extremely high-temperature environments. These ceramic foams feature an interconnected pore structure, achieving a porosity of 75.2% and a density of 0.41 g/cm3. The foam demonstrates low thermal conductivity of 0.21 W·m–1·K–1, promising broadband electromagnetic wave absorption with a minimum reflection loss (RLmin) of −33.9 dB and an effective absorption bandwidth (EAB) of 3.7 GHz. Additionally, it exhibits high load-bearing strength of 26 MPa. The exceptional multifunctionality of these ceramic foams is primarily due to their interconnected pore structure and the solid solution strengthening of TiC in ZrC ceramics. Notably, the ceramic foam also shows remarkable high-temperature resilience. After undergoing five thermal cycles at 1600 °C, the material maintains its structural integrity and performance stability, with electromagnetic absorption characteristics dropped to RLmin of −28.7 dB, along with a mechanical strength of 9 MPa.