Synthesis, pyrolysis of a novel liquid SiBCN ceramic precursor and its application in ceramic matrix composites

详细信息    查看全文

• 作者：Hui Zhao^a ; Lixin Chen^a ; ^{lixin@nwpu.edu.cn} ; Xingang Luan^b ; ^{xgluan@nwpu.edu.cn} ; Xiaofei Zhang^a ; Jin Yun^a ; Tingting Xu^a
• 关键词：SiBCN ceramic ; Polyborosilazane ; Soluble liquid precursor ; High-temperature resistance ; Ceramic matrix composite
• 刊名：Journal of the European Ceramic Society
• 出版年：2017
• 出版时间：April 2017
• 年：2017
• 卷：37
• 期：4
• 页码：1321-1329
• 全文大小：3481 K
• 卷排序：37

文摘

SiBCN ceramic precursor, polyborosilazane, was synthesized through a novel method which used sodium borohydride as boron source. Vinyl silazane with SiCl was converted to vinyl silazane with SiH structure, followed by hydroboration reaction and subsequent high-temperature reaction to form soluble polyborosilazane liquid. The process of precursor-to-ceramic conversion was almost completed before 800 °C and the cross-linked polyborosilazane precursor exhibited higher ceramic yield 75.6% at 1200 °C. The SiBCN ceramic annealed at 1400 °C contained BN, SiN and SiC bonds with smooth and dense surface and still retained principally amorphous structure up to 1600 °C. In addition, the viscosity of the polyborosilazane was 65 mPa.s, which can efficiently prepare ceramic matrix composite by means of precursor infiltration and pyrolysis (PIP). The density of as-obtained ceramic matrix composite (CMC) was 1.82 g/cm3, and the average bending strength, bending modulus and tensile strength were 265.2 MPa, 37.5 GPa and 158.6 MPa, respectively.