Method for producing flexible tooling for casting a ceramic core

Patent metadata

Field	Value
Publication number	US-12330210-B2
Application number	US-201917772873-A
Country	US
Kind code	B2
Filing date	Nov 1, 2019
Priority date	Nov 1, 2019
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

A method for producing a flexible tooling liner for casting a ceramic core is presented. The method includes the steps of producing a three-dimensional (3D) reference object representative of a ceramic core to be cast, disposing the reference object into a containment vessel configured to receive a liquid flexible tooling material, filling the containment vessel with the liquid tooling material so that the reference object is encapsulated by the liquid tooling material on the surface whose topography is intended to be imparted, allowing the liquid tooling material to cure, and separating the cured flexible tooling along a parting surface into opposing portions and removing the reference the reference object.

First claim

What is claimed is:

1. A method for producing a flexible tooling liner for casting a ceramic core, comprising:
producing a reference object representative of the ceramic core to be cast;
disposing the reference object into a containment vessel configured to receive a liquid flexible tooling liner material within a cavity defined by the containment vessel and the reference object, wherein the reference object comprises a separation feature, wherein the reference object is configured to separate the cavity into a 1st volume that is located on a 1st side of the separation feature and a 2nd volume that is located on a 2nd side of the separation feature opposite the 1st side, that is sealed from the 1st volume, and that is separated from the 1st volume by a thickness of the separation feature;
filling the 1st volume and the 2nd volume with the liquid flexible tooling liner material so that both a 1st side and a 2nd side of the reference object are encapsulated by the liquid flexible tooling liner material on the surfaces whose topography is intended to be imparted in the flexible tooling liner formed upon the curing of the liquid flexible tooling liner material;
allowing the liquid flexible tooling liner material to cure to form a cured flexible tooling liner comprising a 1st flexible mold portion formed by the 1st volume and a 2nd flexible mold portion that is formed by the 2nd volume and that is discrete from the 1 st flexible mold portion; and
separating the 1st flexible mold portion from the 2nd flexible mold portion and removing the reference object;
wherein when assembled together the 1st flexible mold portion and the 2nd flexible mold portion are configured to abut each other and to thereby form the ceramic core therebetween in a shape of the reference object without the separation feature.

2. The method as claimed in claim 1 , the producing of the reference object accomplished by a process selected from the group consisting of additive manufacturing, molding, and machining.

3. The method as claimed in claim 1 , wherein the thickness (t) lies in a range of 0.10 to 0.30 in.

4. The method as claimed in claim 1 , wherein the liquid flexible tooling liner material is uncured silicone rubber.

5. The method as claimed in claim 1 , wherein the separation feature comprises an alignment feature, for the alignment of the reference object within the containment vessel, the alignment feature selected from the group consisting of an extended tab or stem, protrusion, embossment, and a tongue and groove interface.

6. The method 10 as claimed in claim 1 , wherein the separation feature comprises a font and feed channel geometry so that a ceramic slurry may be fed into the flexible tooling liner in order to produce the ceramic core.

7. The method as claimed in claim 1 , further comprising modifying the geometry of the reference object by installing an insert having a contoured geometry within a cavity in the reference object, wherein the contoured geometry is a different geometry than the replaced geometry of the reference object.

8. The method as claimed in claim 1 , wherein the reference object includes features representative of a gas turbine blade or vane.

9. The method as claimed in claim 1 , wherein the separation feature is configured to form alignment features in the 1st flexible mold portion and the 2nd flexible mold portion that align the 1st flexible mold portion and the 2nd flexible mold portion with each other when the 1st flexible mold portion and the 2nd flexible mold portion are assembled together.

10. A method of forming a ceramic core for an investment casting from a flexible tooling liner, comprising:
producing a reference object representative of the ceramic core to be cast and further comprising a separation feature;
disposing the reference object into a containment vessel configured to receive a liquid tooling material in a cavity defined by the containment vessel and the reference object, wherein the reference object is configured to separate the cavity into a 1 st volume that is located on a 1st side of the separation feature and a 2nd volume that is located on a 2nd side of the separation feature opposite the 1st side, that is sealed from the 1st volume, and that is separated from the 1st volume by the separation feature;
filling the 1st volume and the 2nd volume with the liquid tooling material so that both a 1st side and a 2nd side of the reference object sare encapsulated by the liquid tooling material on the surfaces whose topography is intended to be imparted in the flexible tooling liner formed upon the curing of the liquid tooling material;
allowing the liquid tooling material to cure to form a cured flexible tooling liner comprising a 1st mold portion formed by the 1st volume and a 2nd flexible mold portion that is formed by the 2nd volume and that is discrete from the 1st flexible mold portion;
separating the 1st flexible mold portion from the 2nd flexible mold portion and removing the reference object;
preparing the flexible tooling liner to receive a ceramic material;
casting the ceramic material in the flexible tooling liner to form the ceramic core in a shape of the reference object without the separation feature; and
removing the cured ceramic core from the flexible tooling liner.

11. The method as claimed in claim 10 , wherein the preparing includes aligning and supporting the opposing portions of the flexible tooling liner.

12. A method for producing a contoured flexible tooling liner for casting a ceramic core by controlling a thickness of a flexible tooling liner, comprising:
producing a reference object representative of the ceramic core to be cast and further comprising a separation feature;
disposing the reference object into a containment vessel configured to receive a liquid flexible tooling liner material within a cavity defined by the containment vessel and the reference object, wherein the reference object is configured to separate the cavity into a 1st volume that is located on a 1st side of the separation feature and a 2nd volume that is located on a 2nd side of the separation feature opposite the 1st side, that is sealed from the 1st volume, and that is separated from the 1st volume by the separation feature;
producing a contoured tooling object configured to form an outward facing surface of an inner liner or to form an inward facing surface of an outer liner;
disposing the contoured tooling object into the containment vessel so that an inner cavity is defined by the reference object and the contoured tooling and an outer cavity is defined by the contoured tooling and the containment vessel, wherein a 1st portion of the inner cavity and a 1st portion of the outer cavity are disposed in the 1st volume, and a 2nd portion of the inner cavity and a 2nd portion of the outer cavity are disposed in the 2nd volume;
filling the inner cavity or the outer cavity with the liquid flexible tooling liner material;
allowing the liquid flexible tooling liner material to cure thereby creating a first liner comprising a first liner 1st portion disposed in the 1st volume and a first liner 2nd mold portion disposed in the 2nd volume;
removing the contoured tooling object from the cavity of the containment vessel;
filling the remaining cavity a remainder of 1st volume and a remainder of the 2nd volume with the liquid flexible tooling liner material;
allowing the liquid flexible tooling liner material to cure within the remainder of the 1st volume and the remainder of the 2nd volume, thereby creating a second liner comprising a second liner 1 st portion disposed in the remainder of the 1st volume and a second liner 2 nd portion disposed in the

Assignees

• Siemens Energy Global Gmbh & Co Kg

Inventors

• Vitello Travis John
• Richerson Lara
• Bibb Douglas
• Gangle Scott
• Bruce Robert
• Doran Ian T
• Duren Christopher
• Belling Andrew
• Mcdonald Wayne J

Classifications

• B22C7/02

  Lost patterns · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B22C9/24

  for hollow articles · CPC title

• B22C9/10 Primary

  Cores; Manufacture or installation of cores {(breaker cores B22C9/084)} · CPC title

• B22C9/04

  Use of lost patterns · CPC title