Gas Turbine Sealing Interface Repair via Low-Melting Additive Diffusion

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Solution Overview

Problem

Gas turbine engines face efficiency losses due to erosion and wear of sealing interfaces in BOAS assemblies, leading to incomplete seals and air leakage, which existing repair methods fail to adequately address.

Innovation Solution

A repair method using a combination of parent and additive materials, where the additive material lowers the melting temperature of the parent material, allowing for a metallurgical bond and diffusion into a shaped cavity to rebuild the sealing interface, maintaining the original melting point and temperature resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing repair methods are used for damaged sealing interfaces, then some repair capability is provided, but the repair is inadequate and fuel efficiency losses persist

Engineering Contradiction:
Improvesealing interface integrityVSAvoidfuel efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the melting temperature parameter of the repair material by adding alloying elements (e.g., nickel, chromium, cobalt, molybdenum, tungsten, boron) to match or exceed the melting point of the original sealing interface material. This allows the repair material to remain stable at operating temperatures while still being applicable at lower temperatures, ensuring both reliable sealing and energy efficiency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite repair materials consisting of base metals (such as cobalt, nickel, or iron) combined with alloying elements to create a material that replicates the properties of the original sealing interface. This composite approach ensures the repair material achieves adequate melting point, strength, and sealing capability, thereby restoring fuel efficiency while maintaining reliability.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If repair material with low melting temperature is used, then easier application is achieved, but the original temperature resistance is lost

Engineering Contradiction:
Improverepair material applicationVSAvoidmelting point
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent modifies the melting temperature parameter of the repair material through controlled addition of alloying elements. These elements elevate the melting point of the base material to match or exceed that of the original sealing interface, ensuring the repair material can withstand operating temperatures while remaining applicable at lower temperatures for ease of manufacturing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different material compositions to different regions or aspects of the repair process. The base material provides low-temperature applicability, while alloying elements distributed throughout provide high-temperature resistance, creating a locally optimized material structure that satisfies both ease of manufacture and temperature resistance requirements.

Inventive Principle:
Principle #3Local quality

3Ease of repair

If the sealing interface is not properly repaired, then repair simplicity is maintained, but air leakage occurs and fuel efficiency is lost

Engineering Contradiction:
Improverepair process simplicityVSAvoidair leakage
Core Design Contradiction:
Ease of repairVSLoss of energy

Solution Approach 1:

The patent optimizes the melting temperature and compositional parameters of the repair material to enable effective sealing at lower temperatures. This allows for simpler repair processes while ensuring adequate sealing performance that prevents air leakage and maintains fuel efficiency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The repair material is formulated to self-bond metallurgically to the damaged sealing interface through diffusion and bonding mechanisms. This self-service capability simplifies the repair process by eliminating complex bonding operations while ensuring effective sealing that prevents air leakage and restores fuel efficiency.

Inventive Principle:
Principle #25Self-service

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 effectively repairs damaged sealing interfaces, restoring fuel efficiency by forming a strong bond and reducing the melting temperature of the repair material, while ensuring the reconstructed component retains its original properties.

Implementation Method 1

the additive material lowers the melting temperature of the parent material

Methodology Applied
Scientific EffectMelting temperature reduction: Melting

Implementation Method 2

allowing for a metallurgical bond and diffusion into a shaped cavity

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 3

allowing for a metallurgical bond and diffusion into a shaped cavity

Methodology Applied
Scientific EffectMetallurgical bonding: Diffusion Welding

Data Source

PatentEP2927424B1Repair method
Publication Date: 2019.11.13 UNITED TECH CORP
  • EP2927424B1 patent drawingFigure 1A
  • EP2927424B1 patent drawingFigure 1B~1D
  • EP2927424B1 patent drawingFigure 2A~2B

AI summary

A structural element for repairing a damaged component (112) comprising a shaped cavity (202) configured to receive the damaged component (112) and a repair material, the shaped cavity (202) comprising a material having a first melting point and the repair material comprising a material having a second melting point that is lower than the first melting point. The shaped cavity (202) may comprise a preform for the damaged component (112). The preform may comprise a mold configured to reconstruct the shape of the damaged component (112). The repair material may comprise a first material and a second material, the second material having a melting point that is lower than the first material. The repair material may comprise a Nickel-Boron composition. The repair material may have a melting point that is approximately 40 degrees Fahrenheit (22°C) lower than the melting point of the damaged component (112).