Castings and manufacture methods

Patent metadata

Field	Value
Publication number	US-9802248-B2
Application number	US-201414905904-A
Country	US
Kind code	B2
Filing date	Jul 11, 2014
Priority date	Jul 31, 2013
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A method for casting an article comprises a first region and a second region. The method comprises casting an alloy in a shell, the shell having a casting core protruding from a first metal piece; and deshelling and decoring to remove the shell and core and leave the first region formed by the first piece and the second region formed by the casted alloy.

First claim

What is claimed is:

1. A method for casting an article ( 60 ; 60 - 2 ) comprising a first region ( 82 ; 82 - 2 ) and a second region ( 80 ; 81 ), the method comprising:
mating a pre-formed casting core ( 232 ) to a pre-formed first metal piece ( 220 ) so as to protrude from the first metal piece;
forming a sacrificial pattern material around the casting core;
shelling a combination of the first metal piece, casting core, and the sacrificial pattern material to form a shell ( 290 );
casting an alloy in the shell ( 290 ) with the casting core ( 232 ) protruding from the first metal piece ( 220 ); and
deshelling and decoring to remove the shell and core and leave the first region formed by the first metal piece and the second region formed by the casted alloy.

2. The method of claim 1 wherein:
the decoring leaves one or more passageways ( 90 ) spanning between the first region and the second region.

3. The method of claim 1 wherein:
the casting core ( 232 ) is interfittingly mated with passageways ( 226 ) in the first metal piece.

4. The method of claim 3 further comprising:
adhesive bonding the casting core to the first metal piece.

5. The method of claim 1 wherein:
the first region forms a first portion of an airfoil ( 61 ) and the second region forms a second region of said airfoil.

6. The method of claim 1 wherein:
the first region and the second region have different compositions of nickel-based superalloy.

7. The method of claim 1 wherein:
the first region and the second region have a shared crystalline structure.

8. The method of claim 1 further comprising:
forming the first metal piece by:
casting the first metal piece in a first shell ( 170 ) containing a first casting core ( 122 ); and
at least partially deshelling and decoring the first metal piece.

9. The method of claim 1 wherein the step of forming the sacrificial pattern material comprises:
placing the first metal piece and the casting core in a die;
overmolding a sacrificial pattern material to the casting core in the die; and
removing a combination of the first metal piece, casting core, and pattern material from the die.

10. The method of claim 1 wherein the step of forming the sacrificial pattern material comprises:
placing the casting core in a die;
overmolding a sacrificial pattern material to the casting core in the die; and
removing the casting core and pattern material from the die.

11. The method of claim 10 further comprising:
wax welding the pattern material to the first metal piece.

12. The method of claim 1 further comprising:
locally melting a portion ( 224 ) of the first metal piece prior to the casting so as to propagate a crystalline structure of the first region into the second region upon solidification of the second region.

13. The method of claim 12 wherein:
the locally melting melts no more than 30%, by weight of the first metal piece.

14. The method of claim 12 wherein:
the locally melting melts 10% to 30%, by weight of the first metal piece.

15. The method of claim 1 wherein:
the article is a blade ( 60 ; 60 - 2 );
the first region comprises a first spanwise region of an airfoil of the blade; and
the second region comprises a second spanwise region of the airfoil of the blade.

16. The method of claim 15 wherein:
the first region and second region share a crystalline orientation.

17. The method of claim 15 wherein:
the first region and the second region are of different densities.

18. The method of claim 11 wherein:
the mating is performed after the forming of the sacrificial pattern material.

19. The method of claim 10 wherein:
the mating is performed after the forming of the sacrificial pattern material.

20. The method of claim 9 wherein:
the mating is performed prior to the forming of the sacrificial pattern material.

Assignees

• United Technologies Corp

Inventors

• Marcin Jr John J
• Bullied Steven J
• Shah Dilip M
• Cetel Alan D

Classifications

• B22D15/00

  Casting using a mould or core of which a part significant to the process is of high thermal conductivity, e.g. chill casting; Moulds or accessories specially adapted therefor · CPC title

• B22D19/16

  for making compound objects cast of two or more different metals, e.g. for making rolls for rolling mills (casting compound ingots B22D7/02) · CPC title

• B22C9/108

  Installation of cores · CPC title

• B22D19/00

  Casting in, on, or around objects which form part of the product (B22D23/04 takes precedence; alumino-thermic welding B23K23/00; coating by casting molten material on the substrate C23C6/00) · CPC title

• B22C7/02

  Lost patterns · CPC title