中文摘要：

以三氯化硼、甲基氢二氯硅烷、六甲基二硅氮烷为起始原料，通过共缩合路径合成了SiBNC陶瓷先驱体一聚硼硅氮烷（PBSZ），将PBSZ在氨气气氛中高温热解可得SiBNC陶瓷．对先驱体及其陶瓷产物的组成、结构和高温结晶性能进行了研究。结果表明，先驱体的骨架结构为-Si—N—B-，其中，B、N以硼氮六环形式存在。1000℃的陶瓷产率为61％，陶瓷中碳含量低于0．5％，具有较好的热稳定性能，能够在1700℃以上保持非晶，在1850℃部分结晶，主要由Si3N4、BN和少量SiC组成，1500℃-1850℃间质量损失约为10％。

英文摘要：

Polyborosilazane （PBSZ）, a precursor to SiBNC ceramic, was synthesized via a one-step condensation reaction using dichloromethylsilane, boron trichloride and hexamethydisilazane as the starting materials. Pyrolysis of the as-synthesized PBSZ in NH3/N2 atmosphere at 1000℃ led to SiBNC ceramics with a yield of 61% and low carbon content （〈0.5%）. The structure and high temperature performance of PBSZ and the corresponding ceramics were investigated in details. The backbone of PBSZ is mainly composed of --Si--N--B-- with some borazine rings. The resulted ceramic shows excellent thermal stability with mass loss of 10% at 1500-1850℃ in nitrogen atmosphere. In addition, the ceramic remains an amorphous state up to 1700℃ and results in small amount of Si3N4, BN and SiC crystallites when heated to 1850℃, which makes it a potential candidate material for the high temperature resistant wavetransparent application.