| 摘要 |
PURPOSE:To provide the filter having heat resistance and thermal impact resistance in combination and is made well usable over a long period of time by using a porous sintered compact which consists essentially of mullite and into which a specific ratio of zircon is incorporated as the filter for molten metal. CONSTITUTION:This filter 1 is composed of the porous sintered compact consisting essentially of the mullite and contg. 10 to 50wt.% zircon. The powder of the zircon (ZrSiO4) is added at 10 to 50wt.% into the powder of 90 to 95wt.% mullite (3Al2O3.2SiO2) and a dispersant, binder, etc., are added to this mixture and the mixture is mixed. The mixture is molded to a honeycomb shape by extrusion molding and is thereafter held for >=2 hours at >=1550 deg.C, by which the mixture is calcined and 5 to 40wt.% monoclinic zirconia crystals are preferably precipitated. Since the monoclinic zirconia crystals existing among the mullite particles relieve stresses, the thermal impact resistance is improved. The mullite has sufficient heat resistance. |
