Granted Patent B2

US 12,528,228 · App. 18/118,443 · Granted Jan 20, 2026

Inventors: Robert A. White, III (Meriden, CT); Andrew Joseph Lazur (La Jolla, CA); Mary Colby (West Hartford, CT); Howard J. Liles (Newington, CT); Robin H. Fernandez (East Haddam, CT)

Assignee: RTX Corporation

B28B21/48B28B7/30C04B41/4531C04B2235/614

Abstract

Claims (30)

1 . A mandrel suitable for supporting an airfoil preform, the mandrel comprising:

a first piece extending along a longitudinal axis of the mandrel, wherein the first piece comprises an aperture extending transverse to the longitudinal axis and disposed adjacent to a first longitudinal end of the first piece, the aperture sized to receive a hook or pin for removing the mandrel from the airfoil preform;

a second piece in physical contact with the first piece at a first interface region, and extending along the longitudinal axis of the mandrel; and

a third piece in physical contact with the first piece at a second interface region, and extending along the longitudinal axis of the mandrel;

wherein the first piece is formed from a first material; and

wherein the second piece is formed from a second material.

2 . The mandrel of claim 1 , wherein the mandrel has an airfoil shape.

3 . The mandrel of claim 2 , wherein the first piece corresponds to a middle section of the airfoil shape, the second piece corresponds to a leading edge section of the airfoil shape, and the third piece corresponds to a trailing edge section of the airfoil shape.

4 . The mandrel of claim 1 , wherein the third piece is formed from a third material.

5 . The mandrel of claim 4 , wherein at least one of the first, second, or third materials comprises graphite, carbon foam, a porous ceramic, molybdenum, or carbon fiber.

6 . The mandrel of claim 5 , wherein at least one of the first, second, or third materials is frangible and at least one of the first, second, or third materials is non-frangible.

7 . The mandrel of claim 1 , wherein at least one of the first, second, or third pieces comprises a tab engageable with an adjacent piece.

8 . The mandrel of claim 1 , wherein the first piece of the mandrel comprises a tab disposed at the first or a second longitudinal end of the first piece, wherein the tab is rotatable to engage a respective first or second longitudinal end of the second piece of the mandrel.

9 . A mandrel suitable for supporting an airfoil preform, the mandrel comprising:

a first piece formed from a first material; and

a second piece formed from a second material and in direct contact with the first piece at an interface region;

wherein the interface region extends along a transverse axis of the mandrel.

10 . The mandrel of claim 9 , wherein at least one of the first or second materials comprises graphite, carbon foam, a porous ceramic, molybdenum, or carbon fiber.

11 . The mandrel of claim 9 , wherein the mandrel is narrowest at the interface region.

12 . The mandrel of claim 9 , wherein the first piece comprises a tab engageable with a slot within the second piece.

13 . A method of forming a ceramic matrix composite (CMC) airfoil, the method comprising:

wrapping a ceramic fabric around the mandrel of claim 1 ;

densifying the ceramic fabric using chemical vapor infiltration (CVI) to form the CMC airfoil; and

removing the mandrel from the CMC airfoil by:

inserting a hook or pin into the aperture of the first piece of the mandrel and pulling the first piece of the mandrel out from a hollow core of the airfoil;

pulling each of the second piece and third piece of the mandrel out from the hollow core of the airfoil following removal of the first piece of the mandrel.

14 . The method of claim 13 , wherein the first piece extends completely through the hollow core of the airfoil and is pulled out from the hollow core along a longitudinal direction of the mandrel.

15 . The method of claim 14 and further comprising:

prior to pulling the second piece out from the hollow core of the airfoil, urging the second piece away from an inner surface of the airfoil along a transverse axis of the mandrel.

16 . The method of claim 13 , wherein pulling the first piece out from the hollow core of the airfoil comprises pulling the first piece in a first direction along a longitudinal axis of the mandrel.

Assignments (2)

Continuity (1)

References Cited (9)