Low Thermal Conductivity Of Aluminum Silicate Fiber Composite Insulation Materials

Along with the rapid development of aeronautic and astronautic industries of high technology, the performance of heat insulation materials need higher requirement. The performances of heat resisting and heat insulating directly influence the exertion of the properties of advanced flight vehicles. Alumina-Silicate ceramic fiber possesses the better heat insulation capability at high temperature, so it is extensively used as excellent high temperature insulators for aerospace industry in a number of grades and forms; however the performance of heat resisting and heat insulating need to be improved in order to meet the heat insulation need of the new equipment. The purpose of the research is to develop the heat-insulating composites with low conductivity based of alumina-silicate fiber to meet the particular need of the equipment.We have prepared highly effective thermal insulations made of the alumina-silica fiber using vacuum filtering molding web technique, Alumina-silicate fiber is used as a matrix; K₂Ti₆O₁₃ whiskers or Silica Aerogels are used as additives for heat insulation; The mix solution of Starch and polyaluminium chloride is used as the bond. In the experiment, we had found the techniques parameters which affect the change of thermal-conductivity. The shapes of heat-insulating composites based of the Alumina-Silicate fiber have been investigated by means of scanning electron microscope (SEM), the heat insulation mechanism of the heat-insulating composites is discussed . Results we get as following:1. The heat-insulating composites with low thermal-conductivity based of the Alumina-Silicate fiber can be prepared using vacuum filtering molding web technique by adding the bend , In which , Alumina-Silicate fiber is used as fibrous materials; K-2Ti₆O₁₃ whiskers as lighter filler for heat insulation. The thermal conductivity of the heat-insulating composites is reduced to 0.077 W/M·K at the temperature of 800℃.2. The quality content of K₂Ti₆O₁₃ whiskers is one of the important factors affecting the change of the thermal conductivity of the composites, The thermal conductivity coefficient of the composites is reduced by adding K₂Ti₆O₁₃ whiskers. The best blend quantity to attain for alumina-silica fiber and K₂Ti₆O₁₃ whiskers is 3:5 in the conditions of our experiment.3. The volume density of the heat-insulating composites is one of the main factors that affects the thermal conductivity. Certificated by the experiment, The most proper volume density small scope is 300...