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- Title
热处理温度对矾土基莫来石材料结构及晶体生长的影.
- Authors
麦海香; 赵飞; 安建成; 王亚利; 连伟康; 胡杨; 葛铁柱; 刘新红
- Abstract
In order to optimize the properties, bauxite based mullite materials were prepared by wet homogenization and high-temperature treatment, using high alumina bauxite (grade Ⅱ, Al2O3 content of about 70 mass%) as the raw material. Effect of the heat-treatment temperature (hold at 1 350-1 650 ℃ for 4 h in air atmosphere) on the phase composition and microstructure of the samples was studied, and the growth mechanism of columnar mullite crystals was discussed. The results show that the mullite conforms to the growth characteristics in a solid-liquid environment:(1)at 1 350-1 500 ℃, a large amount of Al2O3 dissolves into amorphous SiO2, which accelerates the secondary mullitization; at this stage, the supersaturation of the liquid phase is high, and the mullite grains are accompanied by the step growth characteristic; (2)during the re-crystallization sintering stage (1 500-1 650 ℃), the increase of the crystalline phase consumes Al2O3 in the liquid phases, so the liquid phase supersaturation decreases, and the mullite grains exhibit a screw dislocation growth characteristic; (3)as the heat-treatment temperature increases (1 350-1 650 ℃), the viscosity of the liquid phase decreases, thereby reducing the resistance of crystal anisotropic growth, the mullite grains gradually develop into columnar shapes and form a continuous intersecting network structure.
- Subjects
ANISOTROPIC crystals; SCREW dislocations; VISCOSITY; MULLITE; CRYSTAL growth; HEAT treatment; GLASS-ceramics
- Publication
Refractories / Naihuo Cailiao, 2023, Vol 57, Issue 4, p314
- ISSN
1001-1935
- Publication type
Article
- DOI
10.3969/j.issn.1001-1935.2023.04.009