Systems, devices, and methods involving precision component castings

• US 9,387,533 B1
• Filed: 09/29/2015
• Issued: 07/12/2016
• Est. Priority Date: 09/29/2014
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: Mikro Systems, Inc.
• Inventors: Moore, Jon T., Heneveld, Benjamin, Paulus, John R.
• Primary Examiner(s): Yoon, Kevin E
• Application Number:
  US14/868,514
• Time in Patent Office: 287 Days
• Field of Search: 164/23, 164/24, 164/28, 164 34- 36, 164/137, 164/369, 164516-529
• US Class Current: 1/1
• CPC Class Codes: B22C 7/02 Lost patterns
• CPC Class Codes: B22C 9/02 Sand moulds or like moulds for shaped castings
• CPC Class Codes: B22C 9/04 Use of lost patterns
• CPC Class Codes: B22C 9/10 Cores; Manufacture or installation of cores breaker cores B22C9/084
• CPC Class Codes: B22C 9/108 Installation of cores
• CPC Class Codes: B22C 9/24 for hollow articles
• CPC Class Codes: B22D 25/02 by its peculiarity of shape; of works of art cylinders, pistons B22D15/02
• CPC Class Codes: B22D 29/001 Removing cores
• CPC Class Codes: B22D 29/04 Handling or stripping castings or ingots grippers in general, see the relevant subclasses, e.g. B66C
• CPC Class Codes: F01D 25/12 Cooling
• CPC Class Codes: F01D 5/147 Construction, i.e. structural features, e.g. of weight-saving hollow blades F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18
• CPC Class Codes: F01D 5/18 Hollow blades, i.e. blades with cooling or heating channels or cavities structure of hollow blades in general F01D5/147; Heating, heat-insulating or cooling means on blades
• CPC Class Codes: F01D 9/02 Nozzles; Nozzle boxes; Stator blades; Guide conduits , e.g. individual nozzles nozzle boxes F01D9/047
• CPC Class Codes: F05D 2220/30 in turbines
• CPC Class Codes: F05D 2220/32 in gas turbines
• CPC Class Codes: F05D 2230/21 by casting
• CPC Class Codes: F05D 2230/211 by precision casting, e.g. microfusing or investment casting
• CPC Class Codes: F05D 2300/20 Oxide or non-oxide ceramics

Abstract

Certain exemplary embodiments can provide a system, machine, device, manufacture, and/or composition of matter configured for and/or resulting from, and/or a method for, activities that can comprise and/or relate to, investment casting a product in a mold, the product comprising at least one wall, the mold comprising a core, an inner primary shell, and an outer secondary shell.

Claims

1. A method comprising:

investment casting an airfoil in a mold, the airfoil comprising at least one wall, the wall having a thickness within the range of 0.008 inches to 0.015 inches, the mold comprising a core, an inner primary shell, and an outer secondary shell, the core seamlessly combined with the inner primary shell and integral with the inner primary shell yet substantially separated from the inner primary shell by one or more core gaps, the inner primary seamlessly combined with the outer secondary shell and integral with the outer secondary shell yet substantially separated from the outer secondary shell by one or more shell gaps, wherein the one or more core gaps receive molten metal at substantially the same time as the one or more shell gaps.

2. The method of claim 1, wherein:

each of the one or more core gaps is defined by a length, a width that is perpendicular to the length, and a thickness that is perpendicular to the length and the width; and

the thickness of each core gap varies in a predetermined manner along the length and/or width of that core gap.

3. The method of claim 1, wherein:

the inner primary shell is defined by a length, a width that is oriented orthogonal to the length, and a thickness that is oriented orthogonally to the length and the width; and

the thickness varies in a predetermined manner along the length and/or width of the inner primary shell.

4. The method of claim 1, wherein:

each of the one or more shell gaps is defined by a length, a width that is perpendicular to the length, and a thickness that is perpendicular to the length and the width; and

the thickness of each shell gap varies in a predetermined manner along the length and/or width of that shell gap.

5. The method of claim 1, wherein:

the outer secondary shell is defined by a length, a width that is oriented orthogonal to the length, and a thickness that is oriented orthogonally to the length and the width; and

the thickness varies in a predetermined manner along the length and/or width of the outer secondary shell.

6. The method of claim 1, wherein:

the inner primary shell comprises a plurality of features that are configured to increase a strength of the inner primary shell in predetermined portions of the inner primary shell.

7. The method of claim 1, wherein:

the inner primary shell comprises a plurality of features that each have a predetermined shape and each located at a predetermined location.

8. The method of claim 1, wherein:

the inner primary shell comprises a plurality of surface features that are configured to increase a surface area of the inner primary shell.

9. The method of claim 1, wherein:

the inner primary shell comprises a plurality of surface features that are configured to increase a surface roughness at periodic locations on a surface of the inner primary shell.

10. The method of claim 1, wherein:

the inner primary shell comprises a plurality of surface features that each define an undercut in a surface of the inner primary shell.

11. The method of claim 1, wherein:

the inner primary shell comprises a handling connection configured for automated casting.

12. The method of claim 1, wherein:

the inner primary shell and/or outer secondary shell comprises an engineered weakness area configured for facilitating a breaking away of the inner primary shell for removal of the cast airfoil.

13. The method of claim 1, wherein:

the inner primary shell comprises a plurality of surface features that each have a depth within the range of 0.38 mm and 0.66 mm.

14. The method of claim 1, wherein:

the inner primary shell and core are formed from a different material than the outer secondary shell.

15. The method of claim 1, wherein:

the outer secondary shell is formed via a dipping process.

16. The method of claim 1, wherein:

the mold comprises a plurality of prongs that extend between and seamlessly connect the core and the inner primary shell, the plurality of prongs defining a corresponding plurality of film cooling holes in the airfoil, each of the plurality of prongs defines a fillet having a predetermined radius, the fillet located at an intersection of the prong and the inner primary shell or at an intersection of the prong and the core.

17. The method of claim 1, wherein:

the mold comprises a plurality of prongs that extend between and seamlessly connect the core and the inner primary shell, the plurality of prongs defining a corresponding plurality of film cooling holes in the airfoil, each of the plurality of holes defines a single passage that transitions to two or more passages.