US 12,151,282 B2
Effective leaching of alumina-based casting cores
Gary B. Merrill, Orlando, FL (US); Stefan Schell, Erlangen (DE); and Douglas Bingaman, Orlando, FL (US)
Assigned to SIEMENS ENERGY GLOBAL GMBH & CO. KG, Munich (DE)
Appl. No. 17/770,418
Filed by Siemens Energy Global GmbH & Co. KG, Munich (DE)
PCT Filed Oct. 31, 2019, PCT No. PCT/US2019/059112
§ 371(c)(1), (2) Date Apr. 20, 2022,
PCT Pub. No. WO2021/086373, PCT Pub. Date May 6, 2021.
Prior Publication US 2022/0388056 A1, Dec. 8, 2022
Int. Cl. B22C 9/10 (2006.01); B22D 27/04 (2006.01); B22D 29/00 (2006.01); B33Y 10/00 (2015.01); B33Y 70/00 (2020.01); B33Y 80/00 (2015.01); C04B 35/10 (2006.01); C04B 41/53 (2006.01); C04B 41/91 (2006.01)
CPC B22C 9/10 (2013.01) [B22D 27/045 (2013.01); B22D 29/002 (2013.01); B33Y 10/00 (2014.12); B33Y 70/00 (2014.12); B33Y 80/00 (2014.12); C04B 35/10 (2013.01); C04B 41/5353 (2013.01); C04B 41/91 (2013.01); C04B 2235/3217 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method of casting a directionally solidified gas turbine engine component having an internal cooling passage, the method including
using a 3D printing process to form an alumina-based core having an outside surface shape defining a shape of the cooling passage,
directionally solidifying molten metal around the core in a mold to form the component, and
using a leaching process to remove the core from the component to reveal the internal cooling passage,
the method characterized by:
forming the core by printing successive layers of alumina-based material to include a subsurface internal channel, with a shape of the subsurface internal channel being defined by a carrier material within the subsurface internal channel, with the step of forming comprising:
printing a first layer of alumina-based material to form a hollow shell partially defining the outside surface shape and surrounding an inner region partially defining the subsurface internal channel,
printing the carrier material in the inner region, the carrier material in the inner region positioned to at least partially support a second layer of alumina-based material printed over the first layer of alumina-based material to further partially define the outside surface shape, and
allowing the carrier material to remain in the inner region during the step of directionally solidifying molten metal around the core, and
introducing leachate into the subsurface internal channel during the leaching process after removal of the carrier material.
 
5. A method of casting a metal component, the method comprising:
forming a ceramic core by depositing successive layers of material to include a hollow subsurface interior channel, with a shape of the hollow subsurface interior channel being defined by a carrier material within the hollow subsurface interior channel;
casting the metal component around the ceramic core and allowing the carrier material to remain in the hollow subsurface inner channel during a step of directionally solidifying molten metal around the ceramic core; and
removing the ceramic core from the cast metal component using a leaching process wherein a leachate is introduced into the hollow subsurface interior channel after removal of the carrier material.