Investment casting pattern manufacture

a technology of investment casting and pattern, applied in the field of investment casting, can solve the problems of difficult manufacturing of fine features, unsatisfactory internal features of parts, and associated cost of engine efficiency, and achieve the effect of improving engine efficiency and reducing production costs

Active Publication Date: 2007-03-01
RTX CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Such cooling comes with an associated cost in engine efficiency.
The fine features may be difficult to manufacture and / or, once manufactured, may prove fragile.
Assembling the ceramic and refractory metal cores and maintaining their spatial relationship during wax overmolding presents numerous difficulties.
A failure to maintain such relationship can produce potentially unsatisfactory part internal features.
Depending upon the part geometry and associated core(s), it may be difficult to assembly fine refractory metal cores to ceramic cores.
Once assembled, it may be difficult to maintain alignment.
The refractory metal cores may become damaged during handling or during assembly of the overmolding die.
Assuring proper die assembly and release of the injected pattern may require die complexity (e.g., a large number of separate die parts and separate pull directions to accommodate the various RMCs).

Method used

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  • Investment casting pattern manufacture
  • Investment casting pattern manufacture
  • Investment casting pattern manufacture

Examples

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Embodiment Construction

[0018]FIG. 1 shows an exemplary airfoil 20 of a gas turbine engine element. An exemplary element is a blade wherein the airfoil is unitarily cast with an inboard platform and attachment root for securing the blade to a disk. Another example is a vane wherein the blade is unitarily cast with an outboard shroud and, optionally, an inboard platform. Other examples include seals, combustor panels, and the like. The exemplary airfoil 20 has a leading edge 22 and a trailing edge 24. A generally convex suction side 26 and a generally concave pressure side 28 extend between the leading and trailing edges. In operation, an incident airflow is split into portions 500 and 502 along the suction and pressure sides (surfaces) 26 and 28, respectively.

[0019] The exemplary airfoil 20 includes an internal cooling passageway network. An exemplary network includes a plurality of spanwise extending passageway legs 30A-30G from upstream to downstream. These legs carry one or more flows of cooling air (e...

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PUM

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Abstract

At least one feed core and at least one wall cooling core are assembled with a number of elements of a die for forming a cooled turbine engine element investment casting pattern. A sacrificial material is molded in the die. The sacrificial material is removed from the die. The removing includes extracting a first of the die elements from a compartment in a second of the die elements before disengaging the second die element from the sacrificial material. The first element includes a compartment receiving an outlet end portion of a first of the wall cooling cores in the assembly and disengages therefrom in the extraction.

Description

U.S. GOVERNMENT RIGHTS [0001] The invention was made with U.S. Government support under contract F33615-97-C-2779 awarded by the US Air Force. The U.S. Government has certain rights in the invention.BACKGROUND OF THE INVENTION [0002] The invention relates to investment casting. More particularly, the invention relates to investment casting of cooled turbine engine components. [0003] Investment casting is a commonly used technique for forming metallic components having complex geometries, especially hollow components, and is used in the fabrication of superalloy gas turbine engine components. [0004] Gas turbine engines are widely used in aircraft propulsion, electric power generation, ship propulsion, and pumps. In gas turbine engine applications, efficiency is a prime objective. Improved gas turbine engine efficiency can be obtained by operating at higher temperatures, however current operating temperatures in the turbine section exceed the melting points of the superalloy materials...

Claims

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Application Information

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Patent Type & Authority Applications(United States)
IPC IPC(8): B22C9/04
CPCB22C7/02B22C9/04B22C9/064B22C9/103B22C21/14
Inventor SANTELER, KEITH A.
Owner RTX CORP
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