Cooling Aperture Machining for Coated Turbine Engine Components

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Solution Overview

Problem

Existing methods for forming cooling apertures in gas turbine engine components are not optimized for efficient fluid flow and thermal management, leading to suboptimal performance.

Innovation Solution

A manufacturing method involving a preform component with a conductive substrate and non-conductive outer coating, where a preform aperture is created using electrical discharge machining, including a meter section in the substrate and a pilot hole in the coating, with a diffuser section formed in the coating using a secondary machining process to enhance fluid flow and thermal management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a single machining process is used to form cooling apertures in both substrate and outer coating, then the manufacturing process is simple, but the aperture geometry cannot be optimized for efficient fluid flow and thermal management

Engineering Contradiction:
Improveaperture geometry precisionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The cooling aperture formation process is segmented into two distinct stages: first forming a preform aperture in the substrate using electrical discharge machining, then forming the final aperture geometry by removing outer coating material over the preform aperture. This segmentation allows each stage to be optimized independently for its specific function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The preform aperture is created in advance within the substrate before the outer coating is removed. This preliminary action establishes the core geometry and fluid flow path, which then guides the subsequent coating removal process to achieve the final optimized aperture shape.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If electrical discharge machining is used to form the preform aperture in the substrate, then precise meter section geometry is achieved, but the outer coating cannot be machined with the same process

Engineering Contradiction:
Improvemeter section geometry precisionVSAvoidmachining process adaptability
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The preform aperture acts as an intermediary structure that mediates between the electrical discharge machining process (optimized for conductive substrate) and the final aperture geometry (requiring outer coating removal). It provides a template that guides the subsequent coating removal while being created by a process incompatible with the coating material.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the outer coating is removed to form the diffuser section, then fluid flow efficiency is improved, but the coating material is wasted

Engineering Contradiction:
Improvefluid flow efficiencyVSAvoidouter coating material loss
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The outer coating is selectively removed in the diffuser section region to create a porous or open structure that allows fluid flow, while preserving the coating in other regions where it provides protective or functional benefits. This targeted removal optimizes fluid flow without completely sacrificing the coating material.

Inventive Principle:
Principle #31Porous materials

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

The method improves the formation of cooling apertures, enhancing fluid flow and thermal management in turbine engine components, leading to improved performance and efficiency.

Implementation Method 1

A preform aperture is formed in the preform component using an electrical discharge machining electrode

Methodology Applied
Scientific EffectElectrical discharge machining: Electrical Discharge Machining

Implementation Method 2

Fluid is directed through a bore of the electrode against a backside of the outer coating to form a pilot hole in the outer coating

Methodology Applied
Scientific EffectFluid erosion: Erosion

Implementation Method 3

A diffuser section of the cooling aperture is formed in at least the outer coating using a laser machining process

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP4134193A1Forming cooling aperture(s) using electrical discharge machining
Publication Date: 2023.02.15 RTX CORP
  • EP4134193A1 patent drawingFigure 1
  • EP4134193A1 patent drawingFigure 2
  • EP4134193A1 patent drawingFigure 3

AI summary

A manufacturing method is provided. During this method, a preform component (60') is provided for a turbine engine. The preform component includes a substrate (74') comprising electrically conductive material having an outer coating (78') comprising non-electrically conductive material applied over a surface of the substrate. A preform aperture is formed in the preform component using an electrical discharge machining electrode (144). The preform aperture includes a meter section (102) of a cooling aperture (64) in the substrate. The preform aperture also includes a pilot hole (152) in the outer coating. A diffuser section (104) of the cooling aperture is formed in at least the outer coating using a second machining process.