Ceramic mold finishing techniques for removing powder

Abstract

A technique for removing loose powder from the interior surfaces of ceramic molds made using layer manufacturing processes, such as three dimensional printing processes. The interior of a mold is filled with water which is boiled and the particles are entrained in the flow caused by the boiling liquid. In another technique, the mold is immersed in water charged with CO.sub.2 and the pressure rapidly dropped to cause the CO.sub.2 to come out of solution as bubbles which eject the particles. Alternatively, fine particles are introduced into the mold and the mold is agitated to dislodge the particles and the powder so that they can be poured out of the mold. Such technique tends also to remove the surface finish of the mold. Any of the particles which remain can be dissolved in a liquid and removed in the liquid from the mold. Further, the surface finish of the mold can be improved by casting a slip of fine particles on to the surface to form a generally level, and preferably non-conformal, coating on the surfaces.

Dependencies are inferred from the claim text.