Ceramic Core-Shell Mold Filaments for Turbine Cooling Holes

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Solution Overview

Problem

Conventional methods for manufacturing intricate turbine blades with complex internal geometries, such as investment casting, face limitations in achieving fine detail and resolution in ceramic core-shell molds, particularly in producing small filaments for effusion cooling holes, due to the limitations of powder bed and selective laser activation processes.

Innovation Solution

The use of direct light processing (DLP) to create integrated ceramic core-shell molds with thin filaments spanning between the core and shell portions, enabling the production of fine cooling hole patterns in cast components by supporting the polymerization process from the bottom, allowing for thinner filaments and improved resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If powder bed or selective laser activation processes are used to manufacture ceramic core-shell molds, then the manufacturing capability is available, but the resolution and fine detail production capability is insufficient

Engineering Contradiction:
Improveresolution of ceramic core-shell moldVSAvoiddifficulty of producing thin filaments
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces traditional mechanical manufacturing methods (powder bed, selective laser activation) with a chemical solution casting process. This substitution enables the formation of thin filaments and fine details through chemical deposition rather than mechanical layering, achieving superior resolution and fine detail capability in the ceramic core-shell mold

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the manufacturing process parameters by using solution casting with controlled evaporation and drying conditions. This parameter change allows the formation of thin filaments and fine features that cannot be achieved with conventional powder bed or laser activation methods, directly improving manufacturing precision

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If conventional investment casting methods are used, then the casting process can proceed, but the production of intricate internal geometries and fine detail cooling holes is limited

Engineering Contradiction:
Improvecapability to produce intricate internal geometriesVSAvoidfine detail resolution of cooling holes
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent incorporates thin filaments and fine detail features into the ceramic core-shell mold structure before the casting process. These pre-formed features define the intricate internal geometries and cooling hole patterns directly in the final cast component, eliminating the need for post-casting modifications and enabling complex internal structures with high precision

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent divides the mold into core and shell portions with thin filaments connecting them, allowing the filaments to define separate cooling hole pathways. This segmentation enables the production of intricate internal geometries that would be difficult to achieve with a monolithic mold structure

Inventive Principle:
Principle #1Segmentation

3Reliability

If traditional tip pins and ball braze chutes are used, then the casting structure is supported, but the complexity of post-casting modifications increases

Engineering Contradiction:
Improvestructural support during castingVSAvoidnumber of post-casting modifications required
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes traditional tip pins and ball braze chutes from the casting structure by using thin filaments that are integral to the core-shell mold. This extraction eliminates the need for separate support structures and subsequent brazing operations, reducing device complexity while maintaining structural reliability during casting

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the support function traditionally provided by tip pins with the cooling hole definition function by integrating thin filaments into the core-shell mold structure. This merging combines multiple functions into a single element, eliminating post-casting modifications while maintaining casting reliability

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

DLP enables the production of ceramic core-shell molds with sufficient resolution to form cooling holes of small dimensions, enhancing the precision and complexity of internal geometries in cast components, such as turbine blades, by eliminating the need for ball chutes and supporting structures, and allowing for more intricate cooling patterns.

Implementation Method 1

direct light processing (DLP) to create integrated ceramic core-shell molds... by supporting the polymerization process from the bottom

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP3554742B1Multi-piece integrated core-shell casting mold with standoff and/or bumper and method for manufacturing the same
Publication Date: 2022.04.13 GENERAL ELECTRIC CO
  • EP3554742B1 patent drawingFigure 1
  • EP3554742B1 patent drawingFigure 2
  • EP3554742B1 patent drawingFigure 3

AI summary

The present disclosure generally relates to partial integrated core-shell investment casting molds that can be assembled into complete molds. Each section of the partial mold may contain both a portion of a core and portion of a shell. Each section can then be assembled into a mold for casting of a metal part. The partial integrated core-shell investment casting molds and the complete molds may be provided with filament structures corresponding to cooling hole patterns on the surface of the turbine as or stator vane, which provide a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.