Ca-α-Sialon的反应致密化

The Reaction Densification of Ca-α-Sialon

本文通过反应热压制备了单相Ca－α-Sialon材料，研究了Ca－α－Sialon形成的反应致密化过程．不同温度下产物的XRD结果表明，1250℃样品开始软化，1300℃时体系中反应形成了钙铝黄长石相，1500℃时钙铝黄长石重新溶解于液相中，同时形成了Ca－α－Sialon，1600℃时反应完全，原料中各相完全消失，形成了单相Ca－α－Sialon．不同温度下产物的密度表明，伴随着上述反应形成过程，材料经过颗粒重排、溶解-反应-沉淀过程和晶粒生长三个阶段，通过液相烧结达到了致密化．

Ca-a-Sialon was synthesized by hot-pressing technique, and the reaction sequences and densification of Ca-a-Sialon vs sintering temperature were studied. It was found that Ca- a-Sialon isstable. At 1250℃ the reactant mixture stated to soften, and at 1300℃ gehlenite was producedin the system; and at 1500℃ gehlenite was resolved into liquid phase and at the same time Ca-Sialon formed; and at 1600℃ the reaction of formation of Ca-a-Sialon was finished and singlephase Ca-a-Sialon was got. Accompanied by the above sequences, the densification was finishedby liquid sintering through particle rearrangement, solution-reprecipitation, grain growth.