烧结制度对莫来石纤维增强多孔玻璃基复合材料的结构及性能的影响

摘要

Using mullite-fiber as reniforeement, the mullite-fiber-reniforced porous glass matrix composites were prepared by solid-phase sintering. The effect of sintering temperature and holding time on the mierostructure and properties of mullite-fiber-reniforced porous glass matrix composites were researched in detail. The struc- tures and fracture surface morphologies of the composites were characterized by XRD and SEM analyses, the density were tested by the archimedean method. The flexural property of the composites were tested by a uni- versal testing machine. The results show that with the foaming temperature or holding time increased, the aper- ture size of porous glass was increased too, but it will form interconnect hole when the foaming temperature was too high or holding time was too long; the flexural strength and the density reduce with the increase of foaming temperature and holding time; the maximum specific strength was 0. 013m2/s2 when the foaming temperature was 840℃ and the holding time was 20min.%以莫来石纤维为增强体，采用固相烧结法制备了莫来石纤维增强多孔玻璃基复合材料。研究了烧结温度和保温时间对多孔玻璃复合材料的微观结构和性能的影响。采用SEM、XRD等检测手段对复合材料的物相结构及断面的微观形貌进行测试，采用阿基米德法测量其密度，使用万能材料试验机测量其抗折强度。结果表明，随着发泡温度升高、保温时间延长，多孔玻璃的孔径增大，但发泡温度过高或保温时间过长易产生连通孔；抗折强度、密度随着发泡温度的升高或保温时间的延长而降低。当发泡温度为840℃，保温时间为20min时，比强度达到最大值为0．013m2／s2。