Abstract
Single‐crystal seed particles of α‐Fe2O3 were produced by aging ferric nitrate‐derived precipitates. Addition of these particles to boehmite (γ‐AlOOH) sols at concentrations up to 1014 particles/cm3 of dried gel (4.2 wt%) reduced the θ‐ to α‐Al2O3 transformation temperature from 1215° to 1085°C as measured by DTA at a heating rate of 10°/min. The addition of Fe(NO3)3 solution to boehmite at an equivalent Fe2O3 concentration of up to 8.1 wt% lowered the transformation temperature to <970°C. The increased nucleation frequency afforded by Fe2O3 particle and salt additions permitted the development of fully dense submicrometer α‐Al2O3 at <1250°C. Transformation control in alumina is discussed in terms of nucleation frequency and epitaxial effects. 1988 The American Ceramic Society
Original language | English (US) |
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Pages (from-to) | 387-392 |
Number of pages | 6 |
Journal | Advanced Ceramic Materials |
Volume | 3 |
Issue number | 4 |
DOIs | |
State | Published - Jul 1988 |
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry