Ceramic Foam Filters for Filtering Molten Metals and Method for Making the Same

摘要

PURPOSE: Provided is a method for fabricating a ceramic foam filter wherein the method is capable of coating uniformly the inside of a foam with ceramic slurry by eliminating excessive ceramic slurry by a centrifugal separation during a coating process, thereby increasing hardness, porosity and inner surface area of the foam. CONSTITUTION: The method comprises the steps of (a) impregnating flexible mesh foam with ceramic slurry, (b) eliminating excessive slurry on the surface of the foam by a centrifugal separation at 170 to 250 rpm for 7 to 15 sec and drying the foam, (c) repeating the steps (a) and (b) for several times, and (d) calcining the foam at temperature no less than 1400 deg.C, wherein the ceramic slurry comprises 45 to 55 wt.% of silicon carbide, 25 to 35 wt.% of alumina and 15 to 25 wt.% of colloidal silica solution.