Patent ID: 6368525
Filing Date: 2002-04-09
Classification: B22C,C04B

Abstract:
A method for fabricating a gel-cast ceramic article suitable for use as a core in the investment casting of directionally solidified eutectic and superalloy materials, the method comprising the steps of:(i) preparing a ceramic slurry which comprises: (A) a ceramic component, and (B) a solution of a polymerizable binder in a liquid; (ii) forming the slurry into a gel-cast green product of an article-shaped body; (iii) allowing the slurry to gel; (iv) pre-drying the gel-cast green product under conditions of high humidity; (v) freezing the gel-cast green product after pre-drying the gel-cast ceramic article; (vi) subjecting the frozen product to a vacuum for a sufficient time to freeze-dry the product; and (vii) heating the gel-cast green product in an oxygen-containing atmosphere to form a sintered ceramic article.