Castings and Manufacture Methods

Patent metadata

Field	Value
Publication number	US-2018236533-A1
Application number	US-201815958321-A
Country	US
Kind code	A1
Filing date	Apr 20, 2018
Priority date	Jun 3, 2013
Publication date	Aug 23, 2018
Grant date	—

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 coated casting comprising:
a metallic casting having one or more internal passageways; and a ceramic lining along the passageways,
wherein:
the ceramic lining has a porosity in a zone near the casting greater than a porosity in a zone away from the casting.

2 . The coated casting of claim 1 wherein:
the metallic casting at least partially fills the porosity of at least the zone near the casting.

3 . The coated casting of claim 2 wherein:
the zone near the casting comprises a first portion near the casting and a second portion between the first portion and the zone away from the casting, the second portion being less porous than the first portion.

4 . The coated casting of claim 1 wherein:
the metallic casting is a nickel-based superalloy

5 . The coated casting of claim 1 wherein:
the coated casting forms a gas turbine engine component.

6 . The coated casting of claim 1 wherein:
the coated casting has a thermal barrier coating on an exterior surface of differing composition from said coating.

7 . The coated casting of claim 1 wherein:
the casting has an airfoil.

8 . The coated casting of claim 1 wherein:
the zone away from the casting is silica-based; and
the zone near the casting is alumina-based.

9 . The coated casting of claim 1 wherein:
the ceramic lining has a characteristic thickness of 1.0 to 10 mil (25 to 250 micrometers).

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

11 . A method for manufacturing the coated casting of claim 1 , the 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 the metallic casting formed by the metallic material and the ceramic lining formed by the ceramic coating.

12 . The method of claim 11 wherein:
the substrate comprises a molded first ceramic and the coating ceramic comprises a second ceramic different from the first ceramic.

13 . The method of claim 12 further comprising:
applying the second ceramic to the first ceramic by PVD.

14 . The method of claim 11 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.

15 . The method of claim 14 wherein:
the first technique is a vapor deposition and the second technique is not a vapor deposition.

16 . The method of claim 15 wherein:
the second layer comprises a first sublayer ( 52 - 1 ) and a second sublayer ( 52 - 2 ) of differing porosities.

17 . The method of claim 15 wherein:
the second technique is a sol-gel process.

18 . The method of claim 11 wherein:
the coating further comprises a second metallic material ( 200 ) atop ( 202 ) and/or intermixed ( 204 ) with the ceramic.

19 . The method of claim 18 wherein:
at least a majority by weight of the second metallic material ( 200 ) diffuses into the metallic material ( 56 ).

20 . The method of claim 11 further comprising:
applying a coating to an exterior of the casting, but not the interior.

Assignees

• United Technologies Corp

Inventors

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

Classifications

• B22D19/00 Primary

  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

• C23C28/36

  including layers graded in composition or physical properties · CPC title

• F01D5/187

  Convection cooling · CPC title

• C23C28/347

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

• F05D2230/211

  by precision casting, e.g. microfusing or investment casting · CPC title