The design of zirconium and hafnium germanate interphase in SiC_f/SiC composites

详细信息    查看全文

• 作者：V.E. Prokip^a ; ^{prokipvlad@gmail.com} ; A.V. Utkin^a ; I.S. Batraev^b ; N.I. Baklanova^a
• 关键词：Interphase ; Zirconium germanate ; Hafnium germanate ; Ceramic matrix composites ; SiC fiber ; Sol-gel
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：1 April 2017
• 年：2017
• 卷：43
• 期：5
• 页码：4166-4174
• 全文大小：2838 K
• 卷排序：43

文摘

Unidirectional SiCf/SiC minicomposites with SiC matrix derived by polymer-impregnation pyrolysis (PIP), reinforced with SiC fibers coated with zirconium or hafnium germanate were fabricated. Microdebonding indentation tests for SiCf/SiC composites with one- and multilayered germanate interphase were performed. Interfacial shear stress depending on the number of germanate interfacial layers and morphology was determined. The microstructure of the minicomposites and indented fracture surfaces were studied by scanning electron microscopy (SEM). It was stated that an increase in the number of interfacial coatings leads to a decrease in the interfacial frictional stress in SiCf/SiC minicomposites with germanate interphases. The key factor of interphase weakening is the formation of a weak interlayer bonding within the interphase but not germanate layered crystal structure itself. Thus, bonding at the fiber/matrix boundary could be regulated by the number of layers of ZrGeO4 or HfGeO4 in the interphase zone.