Patent ID: 7182121

Claim:
A method for producing investment cast articles, comprising the steps of: (a) providing an investment mold material, (b) providing an effervescent mold solvent solution that is able to permeate the mold material encasing the cast article, and effervesce while interior to the mold material, (c) providing a melt to form the cast article, (d) producing a mold from said investment mold material, having the property, after casting, of sufficiently low strength, and sufficient porosity, to allow removal of the mold from the cast article by said mold solvent solution, where the final modulus of rupture strength of the mold material, after a cast article has been produced, is less than 11% about 15 psi, (e) producing the cast article from melt using said investment mold and allowing to cool, (f) immersing the mold encased cast article in the mold solvent solution for a sufficient period to effect mold removal, whereby said investment material mold is removed from casting thus leaving a casting clean of investment martial residue.