Patent ID: 8980778
Filing Date: 2015-03-17
Classification: B22C,C04B

Abstract:
1. A stable slurry composition suitable for forming investment casting molds by a process involving A) applying at least one coat comprising the composition as a prime slurry onto a wax pattern; B) draining excess slurry from the pattern; and C) stuccoing the resulting part with a refractory grain, the slurry composition comprising: a refractory comprising one or more materials selected from yttria, zirconia, and rare earth metal oxides; a negatively charged or neutral colloidal silica; a soluble organic polymer comprising polyvinyl alcohol wherein the soluble organic polymer is present in an amount of up to about 3.0 wt. % on a dry basis; a cross-linking agent selected from glyoxal dialdehyde and polyamide-epichlorohydrin resin reactive with the soluble organic polymer and present at a level of 0.1-1.0% by weight of the slurry sufficient to prevent resolution upon drying; and water, wherein the slurry composition has a pH of at least 8.5.