Phase Diagram for the SiF4 Join in the System SiO2-Al2O3-SiF4
Phase Diagram for the SiF4 Join in the System SiO2-Al2O3-SiF4
复制标题
DOI:
10.1111/j.1151-2916.1996.tb08734.x
复制
发表时间:
1996-11
影响因子:
3.9
通讯作者:
J. R. Moyer
中科院分区:
文献类型:
--
作者:
J. R. Moyer
Alumina reacts with 1 atm of SiF4 below 660°± 7°C to form A1F3 and SiO2. At higher temperatures the product is a mixture of fluorotopaz and AIF3. Mixtures of fluorotopaz and AIF3 decompose in 1 atm of SiF4 at 973°± 8°C and form tabular α-alumina. The equilibrium vapor pressure of SiF4 above mixtures of fluorotopaz and AlF3 is log p(atm) = 9.198 – 11460/T(K). Fluorotopaz itself decomposes at 1056°± 5°C in 1 atm of SiF4 to give acicular mullite, 2Al2O3.1.07SiO2. Alumina and mullite are stable in the presence of 1 atm of SiF4 above 973° and 1056°C, respectively. The phase diagram of the system SiO2-Al2O3-SiF4 shows only gas-solid equilibria.