Reducing the chemical activity of ceramic molds by reaction sintering

Abstract

In this study, a method for preventing the reaction between ceramic mold and stainless steel that occurs during metal casting process has been introduced. The ceramic molds are produced by using alumina and zircon ceramic powder mixture using silica as a binder which is converted to mullite phase by a reaction sintering process. In the process, the ceramic slurry is prepared by mixing the refractory powder with the suitable binder and gelling agent, poured on to the pattern and after the ceramic mold is gelled, it is removed from the pattern and dried. The ceramic mold is subjected to the reaction sintering at 1600 degrees C for 2 hours in the furnace in order to form mullite (3 Al(2)O(3) SiO(2)) by the reaction between silica and alumina. Stainless steel is poured into the ceramic mold and the moldmetal reaction behavior has been examined in the cast product. Accordingly, burn-on casting defects encountered in stainless steel casting have exclusively been eliminated.