【作者】 王淑峰；

【导师】 刘立强；

【作者基本信息】 山东科技大学 ， 材料学， 2005， 硕士

【摘要】 本文首先提出了高温陶瓷纤维的重要性,综合阐述了氧化物基陶瓷纤维的应用及发展现状,重点说明了莫来石纤维的发展现状和趋势,总结了制备氧化物陶瓷纤维的各种方法,最终确定了采用溶胶—凝胶法进行纤维的制备,以异丙醇铝（Al（i-OC₃H₇）₃,简写为AIP）和氯化铝（AlCl₃·6H₂O）为铝源,正硅酸乙酯（TEOS）为硅源,制备开发了莫来石连续纤维。采用了IR、TG—DTA、XRD、XRF、SEM等手段系统研究了纺丝原液的制备规律和各种特性、纺丝工艺参数、纤维热处理工艺参数等。 研究结果表明:在AIP:AlCl₃=4:1,[H₂O]/[Al+Si]>8（以上均为摩尔比）,pH≤2,用盐酸和醋酸作混合催化剂,0.05%（质量百分比）左右的PVA作纺丝助剂,聚合温度为80—85℃时,能够得到具有较好纺丝性的溶胶;莫来石纤维的热处理过程分两步进行,中低温处理要升温缓慢,一般控制在2℃/min以下,适宜的中温为500℃,在此温度保温20—30min;高温处理要升温较快,控制在3℃/min以上。莫来石凝胶纤维在940℃左右开始有莫来石晶相的衍射峰出现,在热处理过程中没有发现有其它晶相出现,这样就避免了晶相转变时引起的内应力不均衡导致纤维断裂粉化的危险,对纤维性能的提高有利。在1200℃左右处理的莫来石纤维表面光滑,晶粒比较细小,约为100—200nm,这也保证了纤维不至于由于晶粒粗大使纤维太脆而易粉化。最终可以得到有较低孔隙率的莫来石连续纤维。更多还原

【Abstract】 In this paper, the importance of the refractory ceramic fibers is brought forward at first, and the present application and development status of the oxide ceramic fibers are expounded, then the present application status and the trend of the mullite fiber are detailedly explained, the preparation methods of the oxide ceramic fibers are summed up, the Sol-Gel method is confirmed finally to prepare the mullite fiber. The continuous mullite fiber is prepared by Al(i-OC3H7)3 (AIP) and A1C13 (AC) as the sources of the Al, (C2H5)4SiO4 (TEOS) as the source of Si. IR, TG-DTA, XRD, XRF and SEM are adopted to investigate the preparation rules and characters of the spinning solution and the spinning processing parameters and the heat-treating parameters of the mullite fiber.The following conclusions are drawn out: AIP:AC=4:1, [H2O]/[A1 + Si] >8 ( mol ratio), pH≤2, HCl and HAc used as compound catalyst, about 0.05% content ( mass percent) PVA used as spinning assistant, the polymerization temperature chosen 80-85℃, the gotten sol has fine spinning ability. The heat-treating of the mullite fibers is divided into two steps, the heating-up speed rate at moderate and low-temperature is lower than 2℃/min, the suitable moderate temperature is 500℃, the heat retaining time is about 20-30min, the heating-up speed rate is faster than 3℃/min. When the gel fibers are sintered, the diffraction peaks of the mullite crystal are found at about 940℃, and other crystals are not detected in the course of heat treating, so the danger of fibers’ fracturing because of the inner stress of the crystal transition is avoided, which can increase the ability of fibers. The mullite fibers heat-treated at about 1200℃ have smooth surfaces, the crystal grains are small for about 100-200nm, so the danger of fibers’ fragility because of coarse crystals is avoided. Finally, the continuous mullite fibers with little porosity are prepared.更多还原