摘要
将聚碳硅烷先驱丝分别在Ｎ２、Ｈｅ、ＮＨ３和限量空气条件下封装于石英管中，用γ射线辐照至特定剂量后，在高温条件下热解转化为ＳｉＣ陶瓷纤维。结果表明，除在大气条件下辐照因Ｓｉ—Ｈ的氧化在波数３４００ｃｍ－１处产生强吸收峰以外，其它气氛中辐照产物的红外吸收光谱并无明显差异。用ＴＧＡ－ＦＴＩＲ联用技术和气相色谱法检测到热解过程中有ＣＨ４和大量的Ｈ２析出。当吸收剂量达到１３．８ＭＧｙ时，辐照产物已具有良好的不熔化特性，在Ｎ２气流中升温至１２００℃热解烧成后得到有金属光泽的黑色ＳｉＣ纤维，其氧含量（≤１．１ｗｔ％）远低于现有的热氧化不熔化法产物（～１５ｗｔ％）。用扫描电镜观察发现该纤维具有光洁完整的致密形貌结构。
Polycarbosilane (PCS) ceramics precursor fibers were sealed in quartz tubes filled with N 2,
He, NH 3 and air, irradiated to certain dose by γ-ray, then converted to SiC ceramics fibers at
1200℃. Results showed that these gases have little effect on the FTIR spectra of the irradiated
PCS fibers. But serious oxidation of Si H group was observed in the samples that were
irradiated in open air. By using TGA-FTIR coupled analyzing technique and gas
chromatography, CH 4 and a lot of H 2 were detected in the evolved pyrolysis gas. The
irradiated PCS fibers have good infusibility when absorbed dose is higher than 13.8MGy. Metal
like black SiC fibers were obtained by heating the cured PCS filers to 1200℃ in N 2 gas. The
oxygen content (≤ 1.1 wt%) is much lower than conventional SiC fibers fabricated by
oxidation curing method. No defects were observed in the SEM photos of
these SiC fibers.
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
1999年第2期3-8,共6页
Ordnance Material Science and Engineering
基金
国家自然科学基金
