Castings and manufacture methods

Patent metadata

Field	Value
Publication number	US-9975173-B2
Application number	US-201414271764-A
Country	US
Kind code	B2
Filing date	May 7, 2014
Priority date	Jun 3, 2013
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A method includes casting a metallic material ( 56 ) in a mold ( 20 ) containing a core, the core having a substrate ( 40, 44 ) coated with a coating ( 42 ). A removing of the metallic material from the mold and decoring leaves a casting having a layer formed by the coating. The coating has a ceramic having a porosity in a zone ( 50 ) near the substrate less than a porosity in a zone ( 52 ) away from the substrate.

First claim

What is claimed is:

1. A method comprising:
casting a metallic material ( 56 ) in a mold ( 20 ) containing a core, the core having a substrate ( 40 , 44 ) coated with a coating ( 42 ); and
removing the metallic material from the mold and decoring to leave a cast article,

wherein:
the coating or at least one layer thereof reacts with the metallic material and/or survives the decoring to become a portion of the cast article; and
the coating comprises a ceramic having a porosity in a zone ( 50 ) near the substrate less than a porosity in a zone ( 52 ) away from the substrate.

2. The method of claim 1 wherein:
the substrate comprises a molded first ceramic and the coating ceramic comprises a second ceramic different from the first ceramic.

3. The method of claim 2 further comprising:
applying the second ceramic to the first ceramic by PVD.

4. The method of claim 2 wherein:
the first ceramic is silica-based; and
the second ceramic is alumina-based.

5. The method of claim 1 wherein:
the coating ceramic has a characteristic thickness of 1.0 to 10 mil (25 to 250 micrometers).

6. The method of claim 1 wherein:
the coating comprises a first layer ( 50 ) applied by a first technique and a second layer ( 52 ) applied by a second technique, different from the first technique.

7. The method of claim 6 wherein:
the first technique is a vapor deposition and the second technique is not a vapor deposition.

8. The method of claim 7 wherein:
the second layer comprises a first sublayer ( 52 - 1 ) and a second sublayer ( 52 - 2 ) of differing porosities.

9. The method of claim 7 wherein:
the second technique is a sol-gel process.

10. The method of claim 1 wherein:
the coating further comprises a second metallic material ( 200 ) atop ( 202 ) and/or intermixed ( 204 ) with the ceramic.

11. The method of claim 10 wherein:
at least a majority by weight of the second metallic material ( 200 ) diffuses into the metallic material ( 56 ).

12. The method of claim 1 wherein:
the metallic material is a nickel-based superalloy.

13. The method of claim 1 wherein:
the cast article has an airfoil.

14. The method of claim 1 further comprising:
applying a coating to an exterior of the cast article, but not to the interior.

15. The method of claim 1 wherein:
the cast article has one or more internal passageways; and
said portion of the cast article forms a ceramic lining along the passageways,

wherein:
the ceramic lining has a porosity in a zone near the metallic material greater than a porosity in a zone away from the metallic material.

16. The method of claim 15 wherein:
the metallic material at least partially fills the porosity of at least the zone near the metallic material.

17. The method of claim 15 wherein:
the metallic material is a nickel-based superalloy.

18. The method of claim 15 wherein:
the cast article forms a gas turbine engine component.

19. The method of claim 15 wherein:
the cast article has a thermal barrier coating on an exterior surface of differing composition from said ceramic lining.

20. The method of claim 15 wherein:
the cast article has an airfoil.

Assignees

• United Technologies Corp

Inventors

• Prete Thomas W
• Marcin Jr John J
• Beers Russell A

Classifications

• F01D5/187

  Convection cooling · CPC title

• C23C28/36

  including layers graded in composition or physical properties · CPC title

• C23C28/048

  with layers graded in composition or physical properties · CPC title

• C23C28/347

  with layers adapted for cutting tools or wear applications · CPC title

• Y10T428/1317

  Multilayer [continuous layer] · CPC title