| 摘要 |
PURPOSE:To improve the creep characteristic of the jig at high temp. by specifying the bulk density and alumina content of the formed body consisting of the polycrystal high-alumina fiber of specified alumina content and alumina powder of specified particle size in a specified ratio. CONSTITUTION:An aq. slurry contg. 40-60% of the polycrystal high-alumina fiber contg. >=95% alumina, the alumina powder having 0.5-2.0mu average particle diameter and the balance is sucked, dehydrated and formed. The formed body is pressed, dehydrated, and burned to obtain a high-temp. calcining jig having 0.8-2.0g/cm<3> bulk density and contg. >=98% alumina. In this case, when the alumina content of the fiber is controlled to <95%, the SiO2 in the fiber reacts with the material to be burned when an electronic part is calcined, the creep controlling capacity is insufficient at <40%, the sheet making thickness is increased, the load in wet pressing is increased, the fiber is broken, and the creep controlling capacity is reduced at >60%. Meanwhile, the alumina powder having <0.5mu particle size is segregated and the creep characteristic is deteriorated, and sintering does not proceed at >20mu. |
