Ca-α-Sialon的形成特性和显微结构的研究

Formation Behavior and Microstructure of Ca-α-Sialon

由热压工艺制备了组份为ＣａｘＳｉ１２－３ｘＡｌ３ｘＯｘＮ１６－ｘ（０．３≤ｘ≤２．０）的Ｃａ－α－Ｓｉａｌｏｎ陶瓷。本文报道了它的反应过程、相组成、晶胞参数随组份的变化和显微结构的研究结果．研究结果表明，当ｘ≥１．０时，制备的Ｃａ－α’样品的物相由α－Ｓｉａｌｏｎ和ＡＩＮ多型体２１Ｒ组成，其中２１Ｒ的含量随ｘ值的增加而变大．ＴＥＭ的观察结果与物相分析相符，并进一步揭示了在Ｃａ－α－Ｓｉａｌｏｎ样品中长颗粒形貌的α－Ｓｉａｌｏｎ的存在．

Ca-α-Sialons for the compositions MxSi3-xAlxOxN16--x with x ranging from 0.3 to 2.0 wereprepared by hot-pressing technique. The reaction sequence, formation behavior, variation of latticeparameters with the compositions and microstructure of Ca--Sialon were reported in this paper.The result showed that the crystalline phase of Ca- -Sialon in the sintered material consists of --Sialon and AIN-polytypoid 21R when x is equal to or greater than 1.0 and the 21R contentincreases as the x-value increases. TEM observation confirmed the phase assemblages of Ca- Sialon samples and further revealed the existence of elongated 'grain in the materials.