US20030201087A1 - Way to manufacture inserts for steam cooled hot gas path components - Google Patents

Way to manufacture inserts for steam cooled hot gas path components Download PDF

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Publication number
US20030201087A1
US20030201087A1 US10/131,137 US13113702A US2003201087A1 US 20030201087 A1 US20030201087 A1 US 20030201087A1 US 13113702 A US13113702 A US 13113702A US 2003201087 A1 US2003201087 A1 US 2003201087A1
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US
United States
Prior art keywords
casting
inserts
ceramic
hot gas
base superalloy
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/131,137
Inventor
Robert Devine
James Placko
Justin Downs
Jon Schaeffer
Lance Peterson
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General Electric Co
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General Electric Co
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Publication date
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First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=29215557&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=US20030201087(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by General Electric Co filed Critical General Electric Co
Priority to US10/131,137 priority Critical patent/US20030201087A1/en
Assigned to GENERAL ELECTRIC COMPANY reassignment GENERAL ELECTRIC COMPANY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: PETERSON, LANCE G., SCHAEFFER, JON C., DEVINE, ROBERT H., DOWNS, JUSTIN W., PLACKO, JAMES M.
Priority to KR10-2003-0025889A priority patent/KR20030084716A/en
Priority to JP2003119168A priority patent/JP2004003470A/en
Priority to DE60300436T priority patent/DE60300436T2/en
Priority to EP03252630A priority patent/EP1358958B1/en
Publication of US20030201087A1 publication Critical patent/US20030201087A1/en
Abandoned legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D19/00—Casting in, on, or around objects which form part of the product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D29/00—Removing castings from moulds, not restricted to casting processes covered by a single main group; Removing cores; Handling ingots
    • B22D29/001—Removing cores
    • B22D29/002—Removing cores by leaching, washing or dissolving
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/02—Sand moulds or like moulds for shaped castings
    • B22C9/04—Use of lost patterns

Definitions

  • the invention relates to a new way to manufacture inserts for steam cooled hot gas path components.
  • Inserts are required in air and steam cooled nozzles to provide impingement cooling to airfoil walls and ribs.
  • the prior art methods of production of inserts use sheet metal forming operations, including welding and brazing, and electro discharge machining of the holes.
  • the problem with the prior art methods is that the large complicated inserts combined with strict dimensional tolerances result in 3D structures that have a very low yield relative to design specifications.
  • the inventive process casts the inserts to tight tolerance using any ceramic core casting process such as, for example, pressure casting, centrifugal casting, squeeze casting or vacuum casting (also known as counter gravity casting).
  • Counter gravity casting as employed by Hitchiner Manufacturing Co., Inc. of Milford, N.H. uses metal dies with a vacuum pour to help fill thin sections of the casting and eliminate porosity.
  • the core material is then used as a backer during subsequent drilling operations.
  • the core is removed by acid leaching and the cast parts are machined, if necessary, to finish specifications.
  • the inventive method facilitates the production of complicated 3D insert geometries in a Ni-base superalloy with thin walls and tight tolerances.
  • the inventive method also provides for accurate and precise drilling of the cast inserts with improved processing times and fixtures.
  • the inventive method also solves the problems in the prior art by using the ceramic core in the insert casting process to act as a backer for laser drilling.
  • the laser holes then facilitate the use of leachant to quickly remove the core, speeding the manufacturing process.
  • FIG. 1 show a cast insert prior to laser drilling of the insert holes
  • FIG. 2 shows the case insert of FIG. 1 after laser drilling of the insert holes but with the ceramic core still in place
  • FIG. 3 shows the cast and drilled insert immersed in an acid bath for removal of the ceramic core.
  • the inventive method uses, for example, Hitchiner's thin wall casting process to produce the insert geometry from a wax model.
  • the Hitchiner process substitutes counter gravity casting for more conventional casting by, for example, gravity pouring.
  • wax replicas of the desired castings are produced by injection molding. Depending on the size of the castings, multiple wax replicas may be attached to a central waxed stick, termed a sprue, to thereby form a casting assembly. Thereafter, a ceramic shell is formed around the casting or the casting assembly made up of the multiple wax replicas of the desired castings. Next, the ceramic is dried and the wax is melted out creating a negative impression of the casting assembly within the ceramic shell.
  • FIG. 1 schematically shows a cast insert 10 with ceramic core 12 shown in place by dotted lines. Also shown is laser drilling apparatus 14 prior to the drilling process.
  • the cast inserts are made from IN625 (Ni-base superalloy).
  • the ceramic core is not immediately leached out. Instead the casting is put in a fixture for laser drilling holes with the ceramic core still in place.
  • the casting tolerances are such that a fixture can handle a production run without a lot of rework.
  • FIG. 2 schematically shows insert 10 after holes 16 have been drilled by laser drilling apparatus 14 .
  • FIG. 3 schematically shows ceramic 12 being removed by immersing cast insert 10 in acid bath 18 .
  • Another advantage of the inventive method is the reduction in the number of heat treatments that the part goes through relative to current state of the art processing. Reducing heat treatments reduces the amount of distortion caused by residual stresses and results in higher quality.
  • the invention will produce inserts and baffles for hot gas path hardware at a greater level of performance and yield.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Laser Beam Processing (AREA)

Abstract

A method for forming inserts for steam cooled hot gas path components involves casting the inserts and laser drilling the cast inserts with the ceramic casting core still in place. Thereafter, the ceramic core is removed through the use of a leachant. By laser drilling the holes with the ceramic core still in place, the ceramic core acts as a backer during the laser drilling which results in more precise drilling of the inserts and reduced processing time.

Description

    BACKGROUND AND SUMMARY OF THE INVENTION
  • The invention relates to a new way to manufacture inserts for steam cooled hot gas path components. [0001]
  • Inserts are required in air and steam cooled nozzles to provide impingement cooling to airfoil walls and ribs. The prior art methods of production of inserts use sheet metal forming operations, including welding and brazing, and electro discharge machining of the holes. The problem with the prior art methods is that the large complicated inserts combined with strict dimensional tolerances result in 3D structures that have a very low yield relative to design specifications. [0002]
  • The inventive process casts the inserts to tight tolerance using any ceramic core casting process such as, for example, pressure casting, centrifugal casting, squeeze casting or vacuum casting (also known as counter gravity casting). Counter gravity casting as employed by Hitchiner Manufacturing Co., Inc. of Milford, N.H. uses metal dies with a vacuum pour to help fill thin sections of the casting and eliminate porosity. After casting has been completed, the core material is then used as a backer during subsequent drilling operations. Finally, the core is removed by acid leaching and the cast parts are machined, if necessary, to finish specifications. [0003]
  • With the inventive manufacturing method certain commercial and performance needs are met. For example, the inventive method facilitates the production of complicated 3D insert geometries in a Ni-base superalloy with thin walls and tight tolerances. The inventive method also provides for accurate and precise drilling of the cast inserts with improved processing times and fixtures. [0004]
  • The inventive method also solves the problems in the prior art by using the ceramic core in the insert casting process to act as a backer for laser drilling. The laser holes then facilitate the use of leachant to quickly remove the core, speeding the manufacturing process.[0005]
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 show a cast insert prior to laser drilling of the insert holes; [0006]
  • FIG. 2 shows the case insert of FIG. 1 after laser drilling of the insert holes but with the ceramic core still in place; and [0007]
  • FIG. 3 shows the cast and drilled insert immersed in an acid bath for removal of the ceramic core.[0008]
    • DETAILED DESCRIPTION OF THE INVENTION
  • The inventive method uses, for example, Hitchiner's thin wall casting process to produce the insert geometry from a wax model. The Hitchiner process substitutes counter gravity casting for more conventional casting by, for example, gravity pouring. [0009]
  • In the basic investment casting process, wax replicas of the desired castings are produced by injection molding. Depending on the size of the castings, multiple wax replicas may be attached to a central waxed stick, termed a sprue, to thereby form a casting assembly. Thereafter, a ceramic shell is formed around the casting or the casting assembly made up of the multiple wax replicas of the desired castings. Next, the ceramic is dried and the wax is melted out creating a negative impression of the casting assembly within the ceramic shell. [0010]
  • If using the basic casting process, the casting shell is filled with molten metal by gravity pouring. Conversely, in the Hitchiner counter gravity process the ceramic casting shell is placed within a vacuum and dipped into a hot metal melt which is then siphoned up around and into the ceramic casting assembly. After the metal is allowed to solidify on the ceramic casting the vacuum is released and residual metal flows back in to the melt. FIG. 1 schematically shows a [0011] cast insert 10 with ceramic core 12 shown in place by dotted lines. Also shown is laser drilling apparatus 14 prior to the drilling process.
  • Preferably, the cast inserts are made from IN625 (Ni-base superalloy). After the insert are cast into the desired geometry, the ceramic core is not immediately leached out. Instead the casting is put in a fixture for laser drilling holes with the ceramic core still in place. The casting tolerances are such that a fixture can handle a production run without a lot of rework. [0012]
  • The insert is then laser drilled with the ceramic core as a backer. The backer stops backwall strikes and will act as a breakthrough detector. FIG. 2 schematically shows [0013] insert 10 after holes 16 have been drilled by laser drilling apparatus 14.
  • After the large number of holes (˜300 holes/insert) are drilled with laser precision, the ceramic core is leached out with suitable caustics. FIG. 3 schematically shows ceramic [0014] 12 being removed by immersing cast insert 10 in acid bath 18.
  • Another advantage of the inventive method is the reduction in the number of heat treatments that the part goes through relative to current state of the art processing. Reducing heat treatments reduces the amount of distortion caused by residual stresses and results in higher quality. The invention will produce inserts and baffles for hot gas path hardware at a greater level of performance and yield. [0015]
  • While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. [0016]

Claims (12)

What is claimed is:
1. A method of forming inserts for steam cooled hot gas path components in a turbine, said method comprising:
casting the geometrical configuration of the insert; and
laser drilling impingement holes in the cast insert without removing a ceramic casting core of the cast insert.
2. A method as claimed in claim 1, wherein the ceramic casting core is removed by leachant.
3. A method as claimed in claim 2, wherein said casting comprises pressure casting.
4. A method as claimed in claim 2, wherein said casting comprises centrifugal casting.
5. A method as claimed in claim 2, wherein said casting comprises squeeze casting.
6. A method as claimed in claim 2, wherein said casting comprises counter gravity casting.
7. A method as claimed in claim 1, wherein the inserts are made of a Ni-base superalloy.
8. A method as claimed in claim 2, wherein the inserts are made of a Ni-base superalloy.
9. A method as claimed in claim 3, wherein the inserts are made of a Ni-base superalloy.
10. A method as claimed in claim 4, wherein the inserts are made of a Ni-base superalloy.
11. A method as claimed in claim 5, wherein the inserts are made of a Ni-base superalloy.
12. A method as claimed in claim 6, wherein the inserts are made of a Ni-base superalloy.
US10/131,137 2002-04-25 2002-04-25 Way to manufacture inserts for steam cooled hot gas path components Abandoned US20030201087A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US10/131,137 US20030201087A1 (en) 2002-04-25 2002-04-25 Way to manufacture inserts for steam cooled hot gas path components
KR10-2003-0025889A KR20030084716A (en) 2002-04-25 2003-04-24 A new way to manufacture inserts for steam cooled hot gas path components
JP2003119168A JP2004003470A (en) 2002-04-25 2003-04-24 Method for manufacturing insert for component of steam-cooling type high-temperature gas flow passage
DE60300436T DE60300436T2 (en) 2002-04-25 2003-04-25 Process for the production of inserts for steam cooled and hot gas flow exposed components
EP03252630A EP1358958B1 (en) 2002-04-25 2003-04-25 A way to manufacture inserts for steam cooled hot gas path components

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US10/131,137 US20030201087A1 (en) 2002-04-25 2002-04-25 Way to manufacture inserts for steam cooled hot gas path components

Publications (1)

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US20030201087A1 true US20030201087A1 (en) 2003-10-30

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US10/131,137 Abandoned US20030201087A1 (en) 2002-04-25 2002-04-25 Way to manufacture inserts for steam cooled hot gas path components

Country Status (5)

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US (1) US20030201087A1 (en)
EP (1) EP1358958B1 (en)
JP (1) JP2004003470A (en)
KR (1) KR20030084716A (en)
DE (1) DE60300436T2 (en)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9278408B2 (en) 2013-02-27 2016-03-08 Honda Motor Co., Ltd. Laser machining apparatus
US9579714B1 (en) 2015-12-17 2017-02-28 General Electric Company Method and assembly for forming components having internal passages using a lattice structure
US9968991B2 (en) 2015-12-17 2018-05-15 General Electric Company Method and assembly for forming components having internal passages using a lattice structure
US9987677B2 (en) 2015-12-17 2018-06-05 General Electric Company Method and assembly for forming components having internal passages using a jacketed core
US10046389B2 (en) 2015-12-17 2018-08-14 General Electric Company Method and assembly for forming components having internal passages using a jacketed core
US10099284B2 (en) 2015-12-17 2018-10-16 General Electric Company Method and assembly for forming components having a catalyzed internal passage defined therein
US10099276B2 (en) 2015-12-17 2018-10-16 General Electric Company Method and assembly for forming components having an internal passage defined therein
US10099283B2 (en) 2015-12-17 2018-10-16 General Electric Company Method and assembly for forming components having an internal passage defined therein
US10118217B2 (en) 2015-12-17 2018-11-06 General Electric Company Method and assembly for forming components having internal passages using a jacketed core
US10137499B2 (en) 2015-12-17 2018-11-27 General Electric Company Method and assembly for forming components having an internal passage defined therein
US10150158B2 (en) 2015-12-17 2018-12-11 General Electric Company Method and assembly for forming components having internal passages using a jacketed core
US10173264B2 (en) 2013-03-15 2019-01-08 United Technologies Corporation Additive manufacturing baffles, covers, and dies
US10286450B2 (en) 2016-04-27 2019-05-14 General Electric Company Method and assembly for forming components using a jacketed core
US10315248B2 (en) * 2016-11-17 2019-06-11 General Electric Company Methods and apparatuses using cast in core reference features
US10335853B2 (en) 2016-04-27 2019-07-02 General Electric Company Method and assembly for forming components using a jacketed core

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8828214B2 (en) * 2010-12-30 2014-09-09 Rolls-Royce Corporation System, method, and apparatus for leaching cast components
CN106825503A (en) * 2017-03-15 2017-06-13 江苏钜源机械有限公司 The negative-pressure los mould casting method of locomotive engine water cooling cylinder

Citations (3)

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US3694264A (en) * 1970-09-28 1972-09-26 Stuart L Weinland Core removal
US3858290A (en) * 1972-11-21 1975-01-07 Avco Corp Method of making inserts for cooled turbine blades
US5465780A (en) * 1993-11-23 1995-11-14 Alliedsignal Inc. Laser machining of ceramic cores

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Publication number Priority date Publication date Assignee Title
GB2105624A (en) * 1981-09-02 1983-03-30 Rolls Royce Turbine blade manufacture
US6237344B1 (en) * 1998-07-20 2001-05-29 General Electric Company Dimpled impingement baffle

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3694264A (en) * 1970-09-28 1972-09-26 Stuart L Weinland Core removal
US3858290A (en) * 1972-11-21 1975-01-07 Avco Corp Method of making inserts for cooled turbine blades
US5465780A (en) * 1993-11-23 1995-11-14 Alliedsignal Inc. Laser machining of ceramic cores

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9278408B2 (en) 2013-02-27 2016-03-08 Honda Motor Co., Ltd. Laser machining apparatus
US10155288B2 (en) 2013-02-27 2018-12-18 Honda Motor Co., Ltd. Laser machining apparatus
US10173264B2 (en) 2013-03-15 2019-01-08 United Technologies Corporation Additive manufacturing baffles, covers, and dies
US9987677B2 (en) 2015-12-17 2018-06-05 General Electric Company Method and assembly for forming components having internal passages using a jacketed core
US10137499B2 (en) 2015-12-17 2018-11-27 General Electric Company Method and assembly for forming components having an internal passage defined therein
US10046389B2 (en) 2015-12-17 2018-08-14 General Electric Company Method and assembly for forming components having internal passages using a jacketed core
US10099284B2 (en) 2015-12-17 2018-10-16 General Electric Company Method and assembly for forming components having a catalyzed internal passage defined therein
US10099276B2 (en) 2015-12-17 2018-10-16 General Electric Company Method and assembly for forming components having an internal passage defined therein
US10099283B2 (en) 2015-12-17 2018-10-16 General Electric Company Method and assembly for forming components having an internal passage defined therein
US10118217B2 (en) 2015-12-17 2018-11-06 General Electric Company Method and assembly for forming components having internal passages using a jacketed core
US9975176B2 (en) 2015-12-17 2018-05-22 General Electric Company Method and assembly for forming components having internal passages using a lattice structure
US10150158B2 (en) 2015-12-17 2018-12-11 General Electric Company Method and assembly for forming components having internal passages using a jacketed core
US9968991B2 (en) 2015-12-17 2018-05-15 General Electric Company Method and assembly for forming components having internal passages using a lattice structure
US9579714B1 (en) 2015-12-17 2017-02-28 General Electric Company Method and assembly for forming components having internal passages using a lattice structure
US10286450B2 (en) 2016-04-27 2019-05-14 General Electric Company Method and assembly for forming components using a jacketed core
US10335853B2 (en) 2016-04-27 2019-07-02 General Electric Company Method and assembly for forming components using a jacketed core
US10981221B2 (en) 2016-04-27 2021-04-20 General Electric Company Method and assembly for forming components using a jacketed core
US10315248B2 (en) * 2016-11-17 2019-06-11 General Electric Company Methods and apparatuses using cast in core reference features
US11241735B2 (en) 2016-11-17 2022-02-08 General Electric Company Methods and apparatuses using cast in core reference features

Also Published As

Publication number Publication date
KR20030084716A (en) 2003-11-01
JP2004003470A (en) 2004-01-08
DE60300436T2 (en) 2006-02-09
EP1358958B1 (en) 2005-03-30
DE60300436D1 (en) 2005-05-04
EP1358958A1 (en) 2003-11-05

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AS Assignment

Owner name: GENERAL ELECTRIC COMPANY, NEW YORK

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DEVINE, ROBERT H.;PLACKO, JAMES M.;DOWNS, JUSTIN W.;AND OTHERS;REEL/FRAME:012828/0487;SIGNING DATES FROM 20020315 TO 20020322

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION