Improved alumina molten metal filters

摘要: High purity alumina filters suitable for relatively high temperature molten metal filtering applications are prepared by providing a composition comprising fine grain reactive the being free of growth inhibitors in amounts sufficient to inhibit grains during firing; forming into honeycomb structure means; and firing beyond maximum densification employed whereby is fostered. The fired sufficiently long significant particles (from sizes less than about 5 microns between 10 200 microns) creation wide boundaries resulting which further act as crack arrestors. preferably includes burn out material, such graphite, increases porosity product. A preferred 19 parts weight alumina, at least 99.5% pure Al 2 O 3 , 1 part artificial graphite.