CMC Cooling Hole Machining with Multi-Angle Laser Orientation

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Solution Overview

Problem

Conventional laser machining methods for forming cooling holes in ceramic matrix composite (CMC) components of gas turbine engines result in less than optimal geometries due to laser beam clipping, leading to tapered holes and reduced heat transfer effectiveness.

Innovation Solution

A laser machining system that orientates the CMC component in multiple positions to adjust the angle of attack of a conically-shaped laser beam, preventing unwanted clipping and allowing deeper penetration without tapering, thereby achieving precise and uniform cooling hole geometries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional laser machining methods are used to form cooling holes in CMC components, then the holes can be created, but the holes become tapered due to laser beam clipping on the sides and edges of the interior walls

Engineering Contradiction:
Improvecooling hole geometryVSAvoidhole taper
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The patent applies dynamics by making the component movable during the laser machining process. The component is oriented in multiple different positions (orientations) while being lasered, allowing the laser beam to machine different sections at varying angles. This dynamic repositioning prevents the laser beam from clipping the sides and edges of the interior walls, thereby eliminating the taper effect and achieving uniform cylindrical hole geometry throughout the depth of the component.

Inventive Principle:
Principle #15Dynamics

2Length of moving object

If conventional laser machining methods are used, then cooling holes can be formed, but penetration depth is limited as beam clipping and taper angle increase with depth

Engineering Contradiction:
Improvehole depthVSAvoidhole geometry consistency
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

The patent overcomes the depth limitation by dynamically repositioning the component during machining. As the laser beam penetrates deeper into the component, the component is reoriented to different positions, which changes the angle at which the laser beam intersects the interior walls. This prevents beam clipping at greater depths and maintains consistent hole geometry, enabling penetration much deeper than conventional methods while preserving geometric precision throughout the entire depth.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces an additional dimension of control by varying the angular orientation of the component relative to the laser beam. Instead of maintaining a fixed orientation, the component is rotated or tilted to different angles during the machining process. This angular dimension allows the laser beam to access and machine interior walls at depths that would otherwise be blocked by clipping, thereby extending penetration depth while maintaining geometric consistency.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Length of moving object

If the laser beam penetrates deeper into the component, then deeper holes can be formed, but the angle of inclination of the taper increases with depth

Engineering Contradiction:
Improvehole depthVSAvoidtaper angle
Core Design Contradiction:
Length of moving objectVSShape

Solution Approach 1:

The patent dynamically adjusts the component's orientation as a function of depth. At shallower depths, one orientation may be used, but as the laser beam penetrates deeper, the component is reoriented to different positions. This dynamic adjustment compensates for the increasing taper angle that would naturally occur at greater depths, maintaining a consistent cylindrical geometry throughout the entire depth of the hole by preventing beam clipping at each depth level.

Inventive Principle:
Principle #15Dynamics

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 system ensures optimal film effectiveness and deeper penetration of the laser beam, improving the operational service life of CMC components by preventing unwanted clipping and maintaining uniform geometry throughout the cooling holes.

Implementation Method 1

a laser source configured to machine the opening with a conically-shaped laser beam

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP3450086B1Method of and laser system for the manufacture of cooling holes in ceramic matrix composite components
Publication Date: 2021.05.19 GENERAL ELECTRIC CO
  • EP3450086B1 patent drawingFigure 1
  • EP3450086B1 patent drawingFigure 2
  • EP3450086B1 patent drawingFigure 3

AI summary

A system (100) and a method for machining openings (210) in a component (200) are provided. The laser system (100) includes features for machining an opening (210) into a component (200), such as a cooling hole for a CMC component (200) of a gas turbine engine . The component (200) is oriented in a first position (P1) and lasered while oriented in the first position (P1) to form a portion of the opening (210). The component (200) is then oriented to a second position (P2) and lasered while oriented in the second position (P2) to form another portion of the opening (210). The component (200) is alternated between the first and second positions (PI, P2) until the predetermined geometry of the opening (210) is formed. The component (200) is oriented in the first and second positions (PI, P2) such that the laser beam can machine the component (200) without clipping areas that are not desired to be machined.