Porous high-entropy (Zr0.25Hf0.25Nb0.25Ti0.25)C with high strength and uniform pore structure fabricated by freeze-casting

Ultra-high temperature ceramics (UHTCs) are considered as promising thermal insulation materials applied in ultra-high temperature environments (> 2000 °C). However, the high thermal conductivity and high density limit their further development and application. Herein we adopt the strategies of introducing porous structure and high-entropy effect to solve the above problems. Thus porous high-entropy (Zr0.25Hf0.25Nb0.25Ti0.25)C ceramics were prepared. In order to obtain the uniform pore structure and high mechanical property, the camphene-based freeze-casting method was used in this study. The as-prepared porous samples exhibit high porosity of 92.01–73.57