Investment casting composition and method for making the same

摘要

A foamable, ashless investment casting replica composition comprises a foaming compound and a polymer. The foaming compound contains an ammonium salt of a polycarboxylic acid, at least one suspending agent, and may contain at least one carrier resin. During the molding of the replica, the foamed composition avoids shrinkage and thereby maintains its intended shape. In addition, thermal decomposition of the foaming compound yields only volatile gases and therefore leaves no ashes on the interior surface of the ceramic mold.