Systems and methods for reducing the potential for riser backfilling during investment casting

• US 7,882,885 B2
• Filed: 02/18/2008
• Issued: 02/08/2011
• Est. Priority Date: 02/18/2008
• Status: Expired due to Fees

• Current Assignee: Raytheon Technologies Corporation d/b/a RTX (Rtx Corporation)
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Verner, Carl R., Bullied, Steven J., Bochiechio, Mario P.
• Primary Examiner(s): LIN, KUANG Y
• Application Number:
  US12/032,839
• Publication Number:
  US 20090205800A1
• Time in Patent Office: 1,086 Days
• Field of Search: 164/133, 164/35, 164/122.1, 164/122.2, 164/361, 164/516, 164/335
• US Class Current: 164/133
• CPC Class Codes: B22C 9/04 Use of lost patterns
• CPC Class Codes: B22C 9/088 Feeder heads

Abstract

Systems and methods for reducing the potential for riser backfilling during investment casting are provided. In this regard, a representative method for performing investment casting includes: providing a mold having an opening communicating with an interior, the interior having a part cavity and a riser; providing an insert; and using the insert to form a physical barrier to reduce a potential for molten metal to backfill into the riser while the molten metal is introduced into the interior of the mold via the opening.

Claims

1. A method for performing investment casting comprising:

providing a mold having an interior, the interior having a part cavity and a riser communicating therewith;

separating a portion from the mold; and

using the portion as an insert such that the insert forms a physical barrier to reduce a potential for molten metal to backfill from the part cavity into the riser while the molten metal is introduced into the interior of the mold via the opening.

2. The method of claim 1, wherein separating the portion from the mold comprises using a brush wheel.

3. The method of claim 1, wherein, in separating the portion from the mold, an opening communicating with the interior of the mold is revealed.

4. The method of claim 3, wherein, in using the portion as an insert, the portion is inverted and at least partially inserted into the opening of the mold.

5. The method of claim 3, wherein the insert has a frusto-conical intermediate portion with a first opening and a narrower second opening, the second opening being smaller than the opening of the main body mold.

6. The method of claim 1, further comprising forming a component using the molten metal.

7. The method of claim 6, wherein the component is a gas turbine engine component.

8. The method of claim 6, wherein the component is a single crystal metal component.

9. A system for reducing the potential for riser backfilling during investment casting comprising:

a main body mold having an opening communicating with an interior, the interior having a part cavity and a riser, the opening being operative to permit filling of the part cavity with molten metal, the riser interconnecting the part cavity with the interior of the main body mold in a vicinity of the opening; and

an insert sized and shaped to be inserted at least partially into the opening of the main body mold such that the insert forms a barrier operative to reduce the potential for riser backfilling with molten metal introduced into the main body mold via the opening during investment casting wherein the insert has a frusto-conical intermediate portion with a first opening and a narrower second opening, the second opening being smaller than the opening of the main body mold; and

the main body mold has a pourcup located within the interior thereof, the pourcup having an upper opening; and

the second opening of the insert is smaller than the upper opening of the pourcup such that the insert forms a lip, the lip protruding radially inwardly toward a centerline of the pourcup.

10. A system for reducing the potential for riser backfilling during investment casting comprising:

a main body mold having an opening communicating with an interior, the interior having a part cavity and a riser, the opening being operative to permit filling of the part cavity with molten metal, the riser interconnecting the part cavity with the interior of the main body mold in a vicinity of the opening; and

an insert sized and shaped to be inserted at least partially into the opening of the main body mold such that the insert forms a barrier operative to reduce the potential for riser backfilling with molten metal introduced into the main body mold via the opening during investment casting wherein the insert has a frusto-conical intermediate portion with a first opening and a narrower second opening, the second opening being smaller than the opening of the main body mold and wherein the insert has a first annular flange, a second annular flange, and an intermediate portion located between the first flange and the second flange.

11. The system of claim 10, wherein the first flange is larger than the opening of the main body mold such that insertion of the first flange within the opening is prevented.

12. A method for performing investment casting comprising:

providing a mold having an interior, the interior having a part cavity and a riser;

separating a portion from the mold; and

using the portion as an insert such that the insert forms a physical barrier to reduce a potential for molten metal to backfill into the riser while the molten metal is introduced into the interior of the mold via the opening wherein the insert is integrally formed with the mold as a unitary structure and subsequently separated to reveal the opening.

13. A method for performing investment casting comprising:

providing a mold having an interior, the interior having a part cavity and a riser;

separating a portion from the mold; and

using the portion as an insert such that the insert forms a physical barrier to reduce a potential for molten metal to backfill into the riser while the molten metal is introduced into the interior of the mold via the opening wherein the insert has a first annular flange, a second annular flange, and an intermediate portion located between the first flange and the second flange; and

at least one of the first flange and the second flange is used to position the insert relative to the opening of the mold.