Synthesis and characterization of a new liquid polymer precursor for Si–B–C–N ceramics

Oxidation behavior of SiC–SiBCN ceramics

“…1(A); BN, Si 3 N 4 , and SiC phases were detected. Referring to the previous findings [16], SiC, BN, and Si 3 N 4 phases separated out above 1600 1C in the amorphous SiBCN used in this experiment. So, the SiC phase in the sample included SiC precipitated from amorphous SiBCN and added SiC powders.…”

“…The polyborosilazane precursor, made in Institute of Chemistry, Chinese Academy of Sciences, was synthesized by co-condensation reaction of boron trichloride (BTC, 1 M in hexane), methylvinyldichlorosilane (MVDCS), methyldichlorosilane (MDCS) and hexamethyldisilazane (HMDZ). The detailed process for the preparation and pyrolysis of the precursor used in this experiment has been reported by Zhang et al [16]. The polyborosilazane precursor treatment process was as follows: first, the precursor was crosslinked in a corundum tube up to 170 1C at a heating rate of 10 1C/min in nitrogen atmosphere for 2 h, second, the samples was once again pyrolysed in a corundum tube up to 1000 1C at a heating rate of 5 1C/min in argon atmosphere for 2 h, and third, the samples obtained in the previous step was crushed into powders, then the powders passed through a 75 μm sieve.…”

Synthesis and characteristic of SiBCN/HfN ceramics with high temperature oxidation resistance

“…R1 and R2 are vinyl group and/or H, and Me is methyl group. The chemical structure of PBSZ contains BeN ring and backbones includes SieCH 3 , SieNeB and SieCH]CH 2 [22]. The content of B is 0.63 wt %.…”

“…There is no significant difference in the main chemical structures between PBSZ and PBSZHf. In the FTIR spectrum of PBSZHf, typical absorption bands related to NeH, CeH, SieH, BeN, SieN and SieC groups are observed [22]. The characteristic bands are shown in Table 1.…”

“…The backbones are SieN and BeN bonds. The peak at 1469 cm À1 is assigned to BeN stretching and the small peak at 789 cm À1 is ascribed to BeN bending vibration [22]. A broad band at 844 cm À1 is due to SieN bond attached to boron.…”