| 摘要 |
PURPOSE:To produce a beta'-sialon powder having fine particle size, a reduced amount of the glass phase and high purity by adding water and an acidic catalyst to a specific mixture to hydrolyze it, aging the resulting sol, gelatinizing the aged sol, drying the resulting gel and thereafter firing the dried gel in a nitrogen atmosphere. CONSTITUTION:The above mixture is obtained by mixing an aluminum alkoxide such as aluminum sec-butoxide with a alkanolamine compound such as monoethanolamine in amounts to provide 0 to 3 molar ratio of (hydroxyl group(s) in the alkanolamine)/(the aluminum alkoxide). Then a silane coupling agent is added to this mixture in a ratio of the aluminum alkoxide to the silane coupling agent to provide a 0 to 2.34 AL/Si molar ratio to obtain a transparent solution. Thereafter an amount of water of 0.5 to 20 times as much as the amount of the aluminum alkoxide by number of moles and an acidic catalyst such as hydrochloric acid are added to the above solution to hydrolyze it and to obtain a sol. Then the sol is aged, gelatinized and dried, and thereafter fired in a nitrogen atmosphere at >=1400oC for 2 to 5 hours to produce the beta'-sialon powder. |
