莫来石固溶体Al_(4+2x)Si_(2-2x)O_(10-x)合成与其晶体缺陷表征

SYNTHESIS OF MULLITE SOLID SOLUTION Al_(4+2x)Si_(2-2x)O_(10-x) AND CHARACTERIZATION OF ITS CRYSTAL DEFECTS

采用铝型材厂污泥为原料,通过改变原料的配比合成了两种组成的莫来石固溶体:Al4.59Si1.41O9.70和Al4.75Si1.25O9.63。从晶体缺陷的角度探讨了莫来石Al4+2xSi2-2xO10-x的形成机理,并给出了缺陷表达式及缺陷反应方程式。采用PhilipsX’pertplus软件确定莫来石固溶体的晶胞参数和晶胞体积,用RietveldQuantification软件计算各晶相的含量,并用扫描电子显微镜观察了晶相的显微形貌。结果表明:莫来石固溶体的最高含量可达92%,随样品中Al2O3含量增加,莫来石晶胞参数a轴增大,但b轴和c轴变化则没有规律。

Two kinds of mullite solid solution with different compositions, e.g.： Al4.59Si1.41O9.70 and Al4.75Si1.25O9.63, were synthesized using waste aluminum sludge as raw materials by changing the batching ratio of raw materials. The mechanism of the formation of mullite solid solutions was discussed from the viewpoint of crystal defects, and the detailed defects formula and reaction equations were given. The lattice parameters were determined and the amount of crystalline phases was calculated by Philips X＇pert plus and Rietveld Quantification software, respectively. The microstructures of crystalline phases were observed with scanning electron microscopy. The results show that the highest content of mullite solid solution is 92%, and the lattice parameter a increases with the increase of Al2O3 content, but the changes of parameters b and c are irregular.