Sintering of α-Al2O3/quartz, and α-Al2O3/cristobalite related to mullite formation
Sintering of α-Al2O3/quartz, and α-Al2O3/cristobalite related to mullite formation
复制标题
DOI：
10.1016/0272-8842(82)90006-2
复制
发表时间：
1982-10
影响因子：
5.2
通讯作者：
A. Rana;O. Aiko;J. A. Pask
中科院分区：
文献类型：
--
作者：
A. Rana;O. Aiko;J. A. Pask
在1415/sup 0/C条件下，方石英与方石英的反应是不同的，与方石英形成的共晶液体与方石英-Al/亚2/O/亚3/(SiO/亚2/2/方石英)的亚稳相平衡图一致。有了石英，液体首先在石英表面形成，因为在石英转变为方石英的过程中出现了中间液相。这些液体作为形成莫来石的先驱物，通过与..帽α..-Al/sub2/O/sub3/.在类似的烧成条件下，在含有方石英的混合物中早些时候检测到了莫来石，因为莫来石的生长随着在..帽α.-Al/sub2/O/sub3/-方石英界面形成的共晶液体的形成而变得显著，因为它已经饱和了Al/sub2/O/sub3/。烧结动力学受阶跃反应速率的影响。
Cristobalite and quartz react differently in mixtures with ..cap alpha..-Al/sub 2/O/sub 3/ at 1415/sup 0/C. With cristobalite, an eutectic liquid forms in accordance with the metastable phase equilibrium diagram for ..cap alpha..-Al/sub 2/O/sub 3/-SiO/sub 2/ (cristobalite) in the absence of mullite. With quartz, a liquid first forms on the surfaces of quartz because of the occurrence of an intermediate liquid phase on transformation of quartz to cristobalite. These liquids act as precursors to the formation of mullite by reacting with ..cap alpha..-Al/sub 2/O/sub 3/. Mullite was detected earlier in the cristobalite-containing mixtures under similar firing conditions because the growth of mullite becomes significant with the formation of the eutectic liquid at the ..cap alpha..-Al/sub 2/O/sub 3/-cristobalite interface since it is already saturated with Al/sub 2/O/sub 3/. The kinetics of sintering are affected by the rates of the step reactions.