气凝胶
材料科学
陶瓷
复合材料
热导率
扫描电子显微镜
退火(玻璃)
超临界干燥
作者
Jie Wang,Wei Wang,Xuening Liu,Sisi Shang,Yu‐Ting Chen,Lingyan Shi,Sheng Cui
标识
DOI:10.1016/j.ceramint.2023.10.279
摘要
Conventional oxide aerogels have limitations in terms of structural damage and phase transformation at high temperatures. A novel high-entropy (YErYbLu)2SiO5 ceramic aerogel was synthesized by a combination of the sol-gel process, supercritical drying, and high-temperature calcination. The successful synthesis of a high-entropy (YErYbLu)2SiO5 ceramic aerogel in a single phase after calcination at 1250 °C was confirmed by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The high-entropy ceramic aerogel (YErYbLu)2SiO5 still shows excellent structural and phase stability after annealing at 1400 °C. The structurally reconstructed samples (RSO) exhibit low densities ranging from 1.79 to 3.28 g/cm3, room-temperature thermal conductivities between 0.109 and 0.253 W·m-1 K-1, and fracture toughness values ranging from 0.61 to 9.70 MPa. Notably, the lowest thermal conductivity is less than 1/10 of that of the corresponding dense crystalline ceramics. Furthermore, the RSO has a low coefficient of thermal expansion within the temperature range of 360–1200 °C (ranging from 5.84 × 10−6 °C−1 to 7.36 × 10−6 °C−1). The RSO exhibits high residual strength retention after thermal shock testing. These properties position the high-entropy (YErYbLu)2SiO5 ceramic aerogel as a promising candidate for nano-thermal insulation as a porous ceramic material that undergoes structural reconstruction.
科研通智能强力驱动
Strongly Powered by AbleSci AI