| 摘要 |
PURPOSE:To improve durability by mixing principal components of Al2O3 and SiO2 with Cab, Na2O, K2O and ZrO2 at a specific weight ratio, forming the resultant mixture, sintering the formed compact and providing a prescribed bulk density. CONSTITUTION:Al2O3 and SiO2 at a prescribed molar ratio of Al2O3/SiO2 having <=2mum average grain diameter are blended with respective prescribed amounts of CaO, K2O, Na2O and ZrO2 as starting raw materials. A forming assistant such as PVA is then added and mixed with the resultant blend and the obtained mixture is granulated. The obtained granule is subsequently press-formed and burned at 1500-1750 deg. to afford a mullite sintered compact, having the composition of >=97.0wt.% total amount of Al2O3 and SiO2, <=0.2wt.% CaO, <=0.2wt.% total amount of Na2O and K2O and 0.05-2.8wt.% ZrO2 at 1.30-1.85 molar ratio of Al2O3/SiO2 and >=2.96g/cm<3> bulk density, consisting essentially of mullite crystals and excellent in durability. |
