Patent ID: 11945025
Assignee: RTX CORPORATION
Field: Materials, metallurgy (Chemistry)
Classification: CPC B  F | IPC B  F

Claim 18:
19. A casting method comprising:
providing a metallic spacer between two ceramic cores;
molding a sacrificial pattern material over the metallic spacer and two ceramic cores;
shelling the sacrificial pattern material;
firing a shell formed by the shelling;
heating the shell to a casting temperature during which the metallic spacer melts;
after the metallic spacer melts, pouring a casting alloy into the shell; and
removing the shell from the cast alloy, wherein:
the heating of the shell transforms amorphous silica in the two ceramic cores to cristobalite; and
the spacer melts after at least 50% of said amorphous silica in the two ceramic cores have transformed to cristobalite.