High-Entropy Ceramic Aerogel with Ultrahigh Thermomechanical Properties
Materials for extreme-condition thermal insulation need to simultaneously withstand complex thermomechanical stresses while retaining their insulating properties at high temperatures. Ceramic aerogels are attractive candidates, but conventional low-entropy ceramics usually suffer from formidable gra...
محفوظ في:
| المؤلف الرئيسي: | |
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| مؤلفون آخرون: | , , , , , , , |
| منشور في: |
2025
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| الموضوعات: | |
| الوسوم: |
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| الملخص: | Materials for extreme-condition thermal insulation need to simultaneously withstand complex thermomechanical stresses while retaining their insulating properties at high temperatures. Ceramic aerogels are attractive candidates, but conventional low-entropy ceramics usually suffer from formidable grain growth with severe volume shrinkage and strength degradation, resulting in catastrophic failures. Herein, a high-entropy (La<sub>1/4</sub>Sm<sub>1/4</sub>Gd<sub>1/4</sub>Y<sub>1/4</sub>)<sub>2</sub>Zr<sub>2</sub>O<sub>7</sub> (ZLSGY) aerogel is made through an element-phase design, realizing enhanced lattice distortion and sluggish diffusion effects to achieve fine-grain strengthening under extreme conditions. The resulting aerogel exhibits excellent mechanical flexibility, achieving compressive, tensile fracture, and bending strains of 98%, 52%, and 99%, respectively, as well as an ultralow thermal conductivity of 24.79 mW m<sup>–1</sup> K<sup>–1</sup> at 25 °C and 82.19 mW m<sup>–1</sup> K<sup>–1</sup> at 1000 °C. Moreover, the aerogel achieves exceptional thermomechanical stability with a working temperature of up to 1400 °C (less than 3% strength degradation after 10<sup>5</sup> high-temperature deformation cycles). This high-entropy ceramic aerogel presents a promising material system for thermal insulation in extreme environments. |
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