| 摘要 |
PURPOSE:To obtain excellent high-temp. strength and to reduce the production cost by forming the sintered body having specified contents of SiC, CaO and mullite and in which the grain diameter of the mullite is limited. CONSTITUTION:The sintered body consists of SiC, CaO and mullite, the SiC content is controlled to 5-40wt.% and that of CaO to 0.1-1wt.% based on the mullite, and the grain diameter of the mullite is adjusted to 10-100mum. The sintered body is prepared by the following method. Namely, at least two kinds selected from a group consisting of a refined clay mineral, Bayer's alumina, aluminum hydroxide and quartzite are used as the main raw materials, the materials are mixed so that the composition ratio of Al2O3/SiO2 is controlled in a mullite forming range, the raw mixture is wet-crushed so that >=90% of the mixture has <=5mum grain diameter, the SiC having <=50mum grain diameter is added to the raw material by 5-40wt.%, the CaCO3 having <=0.1mum grain diameter is added by 0.1-1wt.% expressed in terms of CaO, the obtained mixture is dried, disintegrated and then formed using an org. binder, and the formed body is sintered at >=1600 deg.C for >=1hr. |
