Patent ID: 11919082
Assignee: ROLLS-ROYCE CORPORATION
Field: Materials, metallurgy (Chemistry)
Classification: CPC B | IPC B

Claim 13:
14. A method for manufacturing a turbine shroud body with at least one undercut region comprising an overhang and an arcuate wall positioned between an arcuate platform and the overhang, the method comprising:
forming a first sacrificial insert comprising a body of a soluble material chosen from polymers, waxes, and metal alloys, wherein the body of the first sacrificial insert comprises an external surface corresponding to at least a portion of a wall of a first undercut region of the at least one undercut region, wherein the first sacrificial insert does not extend beyond the first undercut region;
forming a second sacrificial insert comprising a body of a soluble material chosen from polymers, waxes, and metal alloys, wherein the body of the second sacrificial insert comprises an external surface corresponding to at least a portion of a wall of a second undercut region of the at least one undercut region, wherein the second sacrificial insert does not extend beyond the second undercut region;
placing the first sacrificial insert and the second sacrificial insert in a mold comprising a mold cavity corresponding to a shape of the turbine shroud segment, wherein the first sacrificial insert and the second sacrificial insert are retained in the mold cavity with at least one fastener;
injecting with a metal injection molding (MIM) process a base metal powder mixture into the mold cavity and around the first sacrificial insert and the second sacrificial insert to form a shroud green body with the first undercut region and the second undercut region; and
sintering, while the shroud green body remains in the mold, the shroud green body to form the shroud body and at least partially dissolve the sacrificial insert, wherein the first sacrificial insert and the second sacrificial insert in the mold cavity are at least partially dissolved during or after the sintering step.