(中南大学 材料科学与工程学院, 长沙 410083)
摘 要: 采用差示扫描量热分析(DSC)、 X射线衍射(XRD)分析、 红外光谱(IR)分析和扫描电镜(SEM)观察等方法， 对Si-Al-Zr-O系非晶晶化过程、 晶核剂对晶化过程的影响进行了研究。结果表明： Si-Al-Zr-O系非晶在935~970 ℃和1 100~1 200 ℃分别发生了四方氧化锆和莫来石的析出反应； TiO2和ZrO2作为晶核剂引入对四方氧化锆和莫来石的析出有一定影响； TiO2含量的增加可使四方氧化锆晶相的析出能力显著提高， 而ZrO2含量的增加可提高莫来石晶相的析出能力。 根据晶化过程的研究结果制定了合理的晶化热处理工艺，并获得晶粒大小均匀、 结构致密的微米晶、 纳米晶、 莫来石/SiO2-t-ZrO2复相陶瓷。
关键字: Si-Al-Zr-O系非晶； 晶化行为； 陶瓷复合材料
（ School of Materials Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: The crystallization processes of the Si-Al-Zr-O(SAZ) amorphous bulk were investigated with the aid of DSC, IR, XRD and SEM analysis. The results show that there are two crystallization reactions during the heat treatment for SAZ amorphous bulk. The first crystallization reaction occurs in the range of 935-970 ℃. The tetragonal zirconia is formed. The second crystallization reaction occurs in 1 100-1 200 ℃. The main phases precipitated are mullite and cristobalite. The additions of ZrO2, TiO2 are useful to improve the crystallization behavior. With TiO2, ZrO2 content increase, crystallization temperature decreases. According to the investigation results, a nanometer dense(mullite, cristobalite )/zirconia composite ceramics with uniformly dispersed zirconia not greater than 1 μm are obtained after heattreatment of the homogenous Si-Al-Zr-O amorphous bulk.
Key words: Si-Al-Zr-O system; crystallization behavior; ceramic composite
