莫来石抑制钛酸铝材料热分解的机理研究

STUDY ON MACHENISM OF THE STABILIZING EFFECT OF MULLITE ON ALUMINUM

运用扫描电镜 (SEM)、X -射线衍射仪 (XRD)、能谱仪 (EDS)等现代测试手段 ,从材质的显微结构、晶界晶相组成分析入手 ,对莫来石抑制钛酸铝热分解的作用机理作了较为详细的分析研究 ,探明莫来石抑制钛酸铝热分解的作用机理是 :( 1)在高温下Si4 +进入钛酸铝晶格或间隙中 ,形成固溶化的钛酸铝晶体 ,稳定了晶格 ;( 2 )因莫来石与钛酸铝间的热膨胀差异 ,造成较大的压应力 ( 37.65MPa) ,致使固溶化的钛酸铝晶体更趋稳定。

By SEM, XRD and EDS and son.Methods,the stabilizing effect of mullite on aluminum titanate has been studied in detail by means of analysing the microstructure,compositions of grain boundary and crystal phase.It has been found that the effect machenism of mullite on stability of aluminum titanate is.(1) Si 4+ inter the lattice or its interstitial position of aluminum titanate at high temperature to form solid solution crystal and stabilizing the lattice.(2)The difference of thermal expansion between mullite and aluminum titanate, the larger pressure (37.65MPa) has been formed that solidsolutional aluminum titanate to become more stable.