| 摘要 |
PROBLEM TO BE SOLVED: To obtain alumina having a density nearly equal to the true density, to enable the production on a large scale and to stably supply a product having a complex shape, such a belljar. SOLUTION: The high density alumina sintered body is obtained by adding an amount of 20 to 100 ppm of a MgO component to easily sinterable alumina having the purity of 99.99 wt.%, granulating the resulting mixture, forming, calcining the formed material under the atmosphere and sintering the calcined body at 1,300 to 1,400 deg.C in a hydrogen atmosphere. The suitable alumina sintered body has crystal grain sizes of 0.5 to 5.0 μm and a bulk density of >=3.98 g/cm3. |
