Mechanical and microwave dielectric properties of SiCf/SiC composites with BN interphase prepared by dip-coating process
Mechanical and microwave dielectric properties of SiCf/SiC composites with BN interphase prepared by dip-coating process
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DOI：
10.1016/j.jeurceramsoc.2012.02.009
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发表时间：
2012-08-01
影响因子：
5.7
通讯作者：
Tian, Hao
中科院分区：
文献类型：
--
作者：
Liu, Haitao;Tian, Hao
以硼酸和尿素为前驱体，采用浸涂法制备了SiC纤维增强SiC基（SiCf/SiC）复合材料的BN界面相。结果表明：BN涂层处理后SiC纤维的抗拉强度降低约30%，但BN涂层对SiC纤维的电阻率影响不大；与SiCf/SiC复合材料相比，BN界面相SiCf/SiC复合材料的断裂行为更韧，抗弯强度约为SiCf/SiC复合材料的2倍。显微组织分析表明，BN界面相对削弱界面结合起着关键作用，能显著改善SiCf/SiC复合材料的力学性能。由于SiC和BN之间的介电性质接近，有BN界面相和没有BN界面相的SiCf/SiC复合材料的复介电常数相似。(C) 2012 Elsevier Ltd.版权所有。
The BN interphase of SiC fiber-reinforced SiC matrix (SiCf/SiC) composites was fabricated by dip-coating process with boric acid and urea as precursor. The results show that the tensile strength of SiC fiber decreases about 30% after BN coating treatment, but the BN coating has little influence on the electrical resistivity of SiC fiber. Compared with the as-received SiCf/SiC composites, the SiCf/SiC composites with BN interphase exhibit a toughened fracture behavior, and the flexural strength is about 2 times that of the as-received SiCf/SiC composites. From the microstructural analysis, it can be confirmed that the BN interphase plays a key part in weakening interfacial bonding, which can improve the mechanical properties of SiCf/SiC composites remarkably. Owing to the close dielectric properties between SiC and BN, the complex permittivity of SiCf/SiC composites with and without the BN interphase is similar. (C) 2012 Elsevier Ltd. All rights reserved.