Preparing Method Of Continuous Mullite Fibers

High temperature ceramic materials are applied to more and more fields. One of the significant ways of increasing ceramic mechanical strength is fibre reinforcing ceramic composites. Ceramic matrix composites reinforced with ceramic fibers play an important role in developing high temperature ceramic materials. Mullite is a kind of high refactoriness, has such excellent properties as high refractability, low density, low thermal conductivity, low thermal expansion, high temperature strength retention, high temperature creep resistance, good thermal shock resistance, goode oxidation resistance, and so on. Thus it attracts more and more attention. This dissertation's task is to format continuous mullite fibers with Melt/Drawing on the basis of a detailed review of ceramic fiber process in China and abroad.Pure mullite has high melting point and low vicidity, which leads to poor formation fiber, so it is harder to produce continuous mullite fibers with Melting/Drawing either in equipment or in technique. Therefore, this dissertation discusses how to add the third component in Al₂O₃—SiO₂ system to form continuous mullite fibers.Mullite fibers can be prepared from Al₂O₃—SiO₂ system by adding FeO, Na₂O and MgO with melt process. This dissertation systematically and deeply investigated the behavior of the forming continuous mullite fibers in three systems by means of X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), differential scanning caloremitry (DSC) and scanning electron microscope (SEM) respectively. The main innovations are presented as follows.Continuous fibers are prepared from the system of Al₂O₃—SiO₂—Na₂O (or FeO /or MgO). The fiber structure, indicated by XRD results, is made of a lot of mullites and a certain glass, and the main crystalline phase is proved to be mullite...