A nitride whisker template for growth of mullite in SiC reticulated porous ceramics
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论文类型：期刊论文
发表时间：2017-10-01
发表刊物：CERAMICS INTERNATIONAL
收录刊物：SCIE、EI、Scopus
卷号：43
期号：14
页面范围：11197-11203
ISSN号：0272-8842
关键字：SiC reticulated porous ceramics; Nitride whisker template; Column-liked mullite; Mechanical properties
摘要：Silicon carbide reticulated porous ceramics (SiC RPCs) were fabricated by polymer replica technique. The effects of nitride whisker template on the growth of mullite, the strut structure and mechanical properties of SiC RPCs were investigated. Prepolyurethane (PU) open-cell sponge was first coated by SiC slurry consisting of SiC, reactive Al2O3, microsilica and Si powder, then it was nitridized at 1400 degrees C in a flowing N-2 atmosphere to prepare SiC preforms. Subsequently, these preforms were treated by vacuum infiltration of alumina slurry and fired at 1450 degrees C in air. The results showed that Si2N2O whiskers grew on the surface and in the matrix of SiC preforms after nitridation. The diameter of struts in SiC RPCs increased after vacuum infiltration process because alumina slurry was easily adhered by the surface nitride whiskers. In addition, such whiskers inside the strut of SiC preforms acted as the template to promote the growth of column-liked mullite in SiC RPCs. The mechanical properties and thermal shock resistance of SiC RPCs were greatly improved due to the special interfacial characteristics of multi-layered struts as well as better interlocked column-liked mullite in SiC skeleton.
发表时间：2017-10-01