TRANSFORMATION, MICROSTRUCTURE DEVELOPMENT, AND DENSIFICATION IN ALPHA-FE2O3-SEEDED BOEHMITE-DERIVED ALUMINA

被引:113
作者
MCARDLE, JL [1 ]
MESSING, GL [1 ]
机构
[1] PENN STATE UNIV,DEPT MAT SCI & ENGN,UNIV PK,PA 16802
关键词
D O I
10.1111/j.1151-2916.1993.tb03710.x
中图分类号
TQ174 [陶瓷工业]; TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
Addition of alpha-Fe2O3 seed particles to alkoxide-derived boehmite sols resulted in a 10-fold increase in isothermal rate constants for the transformatiou of gamma- to alpha-Al2O3. Changes in porosity and surface area with sintering temperature showed no effect of seeding on coarsening of the transition alumina gels, but the 200-fold decrease in surface area associated with transformation to alpha-Al2O3 occurred almost-equal-to 100-degrees-C lower in seeded gels compared with unseeded materials. As a result of high nucleation frequency and reduced microstructure coarsening, fully transformed seeded alumina retained specific surface areas >22 m2/g and exhibited narrow pore size distributions, permitting development of fully dense, submicrometer alpha-Al2O3 at almost-equal-to 1200-degrees-C.
引用
收藏
页码:214 / 222
页数:9
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