(1. Key Laboratory of Advanced Ceramics and Machining Technology，School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China) (2. Science Research Academy of Tianjin Building Materials Co., Ltd., Tianjin 300380, China)
The precursorpolyborosilazane (PBSZ) is synthezed via ammonolysis and hydroboration reactions with the precursor molecular structure design. Polyzirconborosilazane (PZrBSZ) is obtained via incorporating Zr atoms into PBSZ network by zirconium/lithium substitution reaction. The PZrBSZ is pyrolysed to SiZrBCN ceramics at 1100 ℃ in a flowing argon atmosphere. The characteristics of zirconium/lithium substitution reaction and the preparation process of PZrBSZ are studied. The chemical structures of the PZrBSZ are analyzed by FTIR. In the FTIR spectra, the characteristic peaks at 584 and 917 cm-1 can be assigned to Zr—N and Si—N—Zr stretching respectively, indicating that zirconium atoms have been successfully introduced into the precursorpolyborosilazane by zirconium/lithium substitution reaction. SEM observes that the ceramics have pores but are compact partly in the crosssection after the pyrolysis of PZrBSZ, which indicated that SiZrBCN ceramics could be prepared by pyrolysis of PZrBSZ.