| Title |
Characteristics of Al2O3 Powder prepared by Sol - Gel Method from Al - Alkoxide |
| Authors |
이정원(Jung Won Lee); 원창환(Chang Whan Won); 천병선(Byung Sun Chun) |
| Abstract |
Transparent alumina was prepared by a sol-gel process. The fabrication process comprises precipitation of aluminum monohydroxide, formation of sol and gel, and calcination of alumina. Thin Al₂O₃coatings were prepared on stainless steel by slow dehydration of an aqueous sol and subsequent heating in air. The alumina coating was transparent by calcination at temperatures up to 1000℃ above which it became opaque due to the formation of α-alumina phase. The total volume of micropores and the volume of pores larger than 80A in the synthesised alumina powder were decreased with increasing calcination temperature upto 1200℃ above which the latter was abruptly increased. The grain size was affected by PH of solution, mole ratio of H₂O/ASB, and reaction temperature. The lattice parameter was not affected by the above three parameters. The alumina powder synthesised by this method has both ultra-fine size and high purity. The high reactivity owing to high surface energy is thought to have contributed to obtaining this alumina powder at a relatively low sintering temperature of 1600℃. |