Solder Void Insert Material for Blocking Braze Flow in Cooling Holes

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Solution Overview

Problem

Conventional insert materials used in soldering processes for gas turbines are porous and unable to effectively block braze alloy from flowing into cooling holes, leading to inefficiencies in crack repair due to their large particle size and inability to fill voids completely.

Innovation Solution

A slurry-based insert material comprising micro-sized and nano-sized metal oxide particles, such as aluminum oxide, with a binder and surfactant, is used to seal voids during soldering, ensuring the molten braze alloy only fills cracks while preventing flow into cooling holes, and can be easily removed post-soldering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If large sized particle insert material is used, then the insert material can be easily applied, but the insert material is porous and allows molten braze alloy to flow into cooling holes

Engineering Contradiction:
Improveease of applicationVSAvoidblocking effectiveness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The insert material is segmented into multiple particle sizes (micro-sized particles of 1-10 μm and nano-sized particles of 0.1-1 μm) rather than using uniform large particles. This segmentation allows the material to pack more densely and fill voids effectively while maintaining ease of application as a slurry

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The insert material uses a composite structure combining micro-sized aluminum oxide particles (providing structural framework) with nano-sized aluminum oxide particles (filling interstices and reducing porosity). This composite approach achieves both ease of application and reliable blocking effectiveness by creating a dense, low-porosity barrier

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If large sized particle insert material is used, then the application process is simplified, but the insert material cannot fill the entire cooling holes and creates grooves and spaces

Engineering Contradiction:
Improveapplication process simplicityVSAvoidfilling completeness
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The particle size distribution is segmented into micro-sized (1-10 μm) and nano-sized (0.1-1 μm) particles. The nano-sized particles fill the gaps between larger particles, enabling complete filling of cooling holes without creating grooves or spaces, while the slurry form maintains application simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The particle size parameters are optimized with a specific ratio of nano-sized to micro-sized particles (0.1-1 μm to 1-10 μm). This parameter change enables the insert material to achieve complete filling precision while maintaining ease of manufacture through slurry application

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If conventional porous insert material is used, then the material can be applied readily, but the molten braze alloy flows into cooling holes and fuses into balls

Engineering Contradiction:
Improvereadiness of applicationVSAvoidbraze alloy intrusion
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The composite structure of micro-sized aluminum oxide particles (providing structural integrity) and nano-sized aluminum oxide particles (reducing porosity to minimal levels) creates a dense barrier that prevents braze alloy intrusion while maintaining readiness of application as a slurry

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The porosity parameter is changed from high (conventional) to low (minimal) through the optimized particle size distribution and ratio. This parameter change prevents braze alloy from penetrating through the insert material while the slurry form maintains ease of operation

Inventive Principle:
Principle #35Parameter changes

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 insert material effectively blocks braze alloy from entering cooling holes, ensuring accurate crack repair and easy removal, even when cracks connect or extend between voids, enhancing the reliability and efficiency of the soldering process.

Implementation Method 1

the insert material is not extendable to fill the entire cooling holes. Grooves are easily appeared within the insert material and spaces are generated between the insert material and the inner surface of the cooling hole

Methodology Applied
Scientific EffectPore filling: Porosity

Implementation Method 2

comprising micro-sized metal oxide particles, nano-sized metal oxide particles, and a binder

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3360637B1Method and insert material for blocking flow of solder material into a void
Publication Date: 2024.02.28 GENERAL ELECTRIC TECH GMBH
  • EP3360637B1 patent drawingFigure 1~3

AI summary

An insert material (18) for blocking flow of solder material into a void (12) of a component (10) during soldering operation is disclosed, which comprises micro-sized metal oxide particles; nano-sized metal oxide particles; and binder. A method for blocking flow of solder material into a void (12) of a component (10) during soldering operation is also disclosed, which comprises preparing insert material (18) in form of slurry comprising micro-sized metal oxide particles, nano-sized metal oxide particles, and binder; charging the insert material (18) into the void (12); drying the insert material (18) in the void (12) which seals the void (12); performing soldering operation; and removing the insert material (18) after soldering operation.