Al与SiO_2玻璃反应的显微组织结构及其演变

THE MICROSTRUCTURES AND THEIR EVOLUTION BETWEEN ALUMINUM AND SILICA GLASS REACTION

Al与SiO2 玻璃之间的反应分为 2个阶段 :在反应初期 ,得到Al/Al2 O3 复合组织 ,数量居多的Al2 O3 以颗粒形式存在 ,Al分布于Al2 O3 间 ,被还原出来的Si在冷却时于Al中以颗粒形式析出 ;随反应时间延长 ,显微组织演变为Al与Al2 O3 互为网络的复合结构 ,Al2 O3网络以更为细小的颗粒组成 ,Si颗粒在等温时依附于Al2 O3 网络析出 .研究表明 ,在反应得到的复合组织前沿存在过渡层 。

Reactions between aluminum and silica glass are divided into two stages. Al/Al 2O 3 composites are obtained at first, in the composites, aluminum distributes between large_size alumina particulate while released silicon particulate deposit in the aluminum matrix under cooling. During the further reaction treatment, the structure of the formed Al/Al 2O 3 composites change into network composite structure in which Al and Al 2O 3 are intermixed, the Al 2O 3 network consists of fine Al 2O 3 particulate and silicon particulate deposits in the Al 2O 3 network during isothermal treatment. Results show that a transient layer, in which Al has a density gradient, exists in the front of reaction composites. It can be considered that the reaction processes are controlled by diffusion of aluminum.