复合添加(Ca,Mg)-α-Sialon的晶胞参数研究

Study on Lattice Parameters of (Ca,Mg)- α-Sialon

利用高分辨率的Ｇｕｉｎｉｅｒ－Ｈａｇｇ相机和计算机控制的底片扫描及数据处理程序系统，测定了复合添加，组份为（Ｃａ０．５Ｍｇ０．５）xＳｉ１２－３ｘAl3xＯｘＮ１６－ｘ（ｘ＝０．３、０．６、１．０和１．４）的α－Ｓｏａｌｏｎ的晶胞参数．材料由热压工艺制备而得．研究结果表明，当ｘ≥１．０时，材料的主晶相为α－Ｓｉａｌｏｎ和含Ｍｇ的ＡlＮ多型体．（Ｃａ，Ｍｇ）－α－Ｓｉａｌｏｎ的晶胞参数明显低于相同组份下的Ｃａ－α－Ｓｉａｌｏｎ的晶胞参数·ＥＤＡＸ的结果进一步给出固溶进入α－Ｓｉａｌｏｎ的包括名义组份中９０％的Ｃａ＋＋和少量的Ｍｇ＋＋，而大部分Ｍｇ＋＋进入ＡlＮ多型体，这一结果为净化α－Ｓｉａｌｏｎ陶瓷的晶界提供了新的有效途径．

By using Guinier-Hagg camera, computer-linked scanner system and associated programs, the lattice parameters ofα-Sialon for the compositions (Ca_0.5Mg_0.5)_xSi_3-xAl_xO_xN16-xwith x ranging from 0.3 to 1.4 were determined. The samples were prepared by hot pressing technique. The results showed that the crystalline phases in the sintered materials consist ofα-Sialonand Mg-containing AIN-polytypoid when x is equal to or greater than 1.0 and the lattice parameters of (Ca,Mg)-a-Sialon are obviously smaller than Ca-α-Sialon with the same compositions.EDAX results further revealed that 90% of added Ca^++ and small amount of Mg^++ are incorporated intoα-Sialon. This result combined with the fact of formation of magnesium-containingAIN-polytypoid phase in (Ca,Mg)- α-Sialon samples can provide a valid approach to reduce theamount of glassy phase at the grain boundary.