Patent ID: 9162279
Filing Date: 2015-10-20
Classification: B22C,B33Y

Abstract:
1. A method of using a mold positive to form a casting mold, the method comprising: forming the mold positive using an additive manufacturing device, the mold positive formed from a material having a first portion that undergoes a solid to gas phase transformation at a first temperature and a second portion that undergoes a solid to gas phase transformation at a second temperature, wherein the first portion is formed within the second portion, and wherein the first temperature is low relative to the second temperature; fabricating the casting mold around the mold positive; and removing the mold positive from the casting mold by increasing a temperature of the mold positive and the casting mold from below the first temperature to above the second temperature such that: the first portion undergoes the solid to gas phase transformation at the first temperature thereby forming voids in the second portion, the voids facilitating expansion of the second portion without damaging the casting mold, and the second portion expands as the temperature increases and then undergoes the solid to gas phase transformation at the second temperature leaving the casting mold empty and ready for casting.