Self-healing behavior and strength recovery of ytterbium disilicate ceramic reinforced with silicon carbide nanofillers
Self-healing behavior and strength recovery of ytterbium disilicate ceramic reinforced with silicon carbide nanofillers
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DOI：
10.1016/j.jeurceramsoc.2019.03.040
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发表时间：
2019-08
影响因子：
5.7
通讯作者：
Son Thanh Nguyen;T. Nakayama;H. Suematsu;Hirokazu Iwasawa;Tsuneo Suzuki;Y. Otsuka;Lingfeng He;Tsuyoshi Takahashi;K. Niihara
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文献类型：
--
作者：
Son Thanh Nguyen;T. Nakayama;H. Suematsu;Hirokazu Iwasawa;Tsuneo Suzuki;Y. Otsuka;Lingfeng He;Tsuyoshi Takahashi;K. Niihara
环境屏障涂层（EBCs）是保护SiC/SiC陶瓷元件在高温应用中免受氧化和热腐蚀的必要条件。二氧化硅在sic增强材料中的挥发是实现这些自裂纹修复陶瓷的主要障碍。Yb2Si2O7-Yb2SiO5-SiC复合材料被认为是一种自修复材料，可以帮助避免这种SiC衰退。在本研究中，通过在氧化环境中进行预裂和退火，研究了该复合材料的裂纹愈合行为。研究了钎料形貌、裂纹尺寸、退火时间和退火温度对裂纹愈合机制的影响。两种主要的裂纹修复机制是用sio2玻璃填充裂纹和由sio2与Yb2SiO5反应引起的yb2si2o7体积膨胀。XRD和EDS分析表明，SiC含量仅为10 vol%，可实现完全裂纹恢复。SiC纳米颗粒是比纳米纤维和纳米晶须更有效的填料。
Environmental barrier coatings (EBCs) are necessary to protect SiC/SiC ceramic components against oxidation and hot corrosion in high-temperature applications. The volatilization of SiO2in SiC-reinforced materials is a major obstacle for the implementation of these self-crack-healing ceramics. The Yb2Si2O7-Yb2SiO5-SiC composite is known as a self-healing material that can help to avoid this SiC recession. In this research, the crack-healing behavior of this composite is investigated by using pre-cracking followed by annealing in an oxidizing environment. The crack-healing mechanism is explored and elucidated as a function of the filler morphology, crack size, annealing time, and annealing temperature. The two main crack-healing mechanisms are the filling of cracks with SiO2glass and the volume expansion of Yb2Si2O7induced by the reaction between SiO2and Yb2SiO5. Full crack recovery is achieved with only 10 vol% SiC, with evidence from XRD and EDS analyses. SiC nanoparticulates are more efficient fillers than nanofibers and nanowhiskers.