Selective Heating of Ceramic-Metal Brazed Joints

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Solution Overview

Problem

Current methods for disassembling modular hybrid gas turbine components, particularly those with ceramic and metal sections joined by brazing, face challenges such as thermal deterioration of metal parts and residue issues during de-brazing, which hinder efficient reuse of metal components and effective replacement of ceramic parts.

Innovation Solution

Exposing the modular hybrid component to an alternating electromagnetic field, specifically with frequencies over 1 kHz, to selectively heat and soften the brazing or soldering joint, allowing for separation of ceramic and metal parts without affecting the metal components, typically using a high-frequency microwave field in a vacuum or low-oxygen atmosphere.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional furnace de-brazing is used to separate ceramic and metal parts, then the brazing joint can be separated, but the metal part suffers thermal deterioration and requires excessive time

Engineering Contradiction:
Improvedisassembly capabilityVSAvoidmetal part integrity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies local quality by using electromagnetic radiation to heat only the ceramic part and brazing joint locally, while the metal part remains relatively cool. This selective heating allows the brazing joint to soften and separate without subjecting the entire metal component to high temperatures, thus maintaining metal part integrity while achieving disassembly capability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent replaces the traditional thermal field (furnace heating) with an electromagnetic field for heating. By using electromagnetic radiation at specific frequencies, the process selectively heats the ceramic part and brazing joint without uniformly heating the metal part, substituting a more precise control mechanism for the crude furnace heating method.

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

2Ease of operation

If traditional furnace de-brazing is used to separate ceramic and metal parts, then the brazing joint can be separated, but the process requires excessive time

Engineering Contradiction:
Improvedisassembly capabilityVSAvoiddisassembly time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The electromagnetic radiation method concentrates energy locally at the ceramic-metal interface and brazing joint, rapidly heating only these specific regions to the required temperature for joint softening. This localized energy delivery achieves separation much faster than conventional furnace heating, which must heat the entire component uniformly, thus reducing disassembly time while maintaining disassembly capability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs periodic electromagnetic radiation at specific frequencies that resonate with or are selectively absorbed by the ceramic material and brazing joint. This periodic energy delivery efficiently transfers energy to the target materials, rapidly achieving the necessary temperature for joint softening and separation, thereby reducing overall process time.

Inventive Principle:
Principle #19Periodic action

3Ease of operation

If high temperatures are applied to separate ceramic and metal parts, then the brazing joint can be softened for separation, but the metal part is damaged

Engineering Contradiction:
Improvejoint separationVSAvoidthermal damage to metal
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The electromagnetic radiation method creates a localized thermal field that concentrates heat at the ceramic part and brazing joint interface. The metal part is either transparent to or has low absorption of the specific electromagnetic frequency used, so it remains relatively cool. This allows the brazing joint to soften and separate without subjecting the metal part to damaging high temperatures, thus achieving joint separation while preventing thermal damage to the metal.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the heating parameter from conventional thermal conduction (furnace heating) to electromagnetic radiation at specific frequencies. By selecting frequencies that are selectively absorbed by ceramic materials and brazing alloys but not by the metal part, the process achieves joint softening at lower overall temperatures, preventing thermal damage to the metal while maintaining separation capability.

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

Enables efficient disassembly of modular hybrid components, allowing for the reuse of metal parts by selectively heating the ceramic sections, which are often replaced, while minimizing thermal impact on the metal components, thus improving the reconditioning process of gas turbine parts.

Implementation Method 1

exposing the modular hybrid component to an alternating electromagnetic field, whereby both parts are heated up differently, and the brazing or soldering joint or field sensitive material between said first part and said second part is affected by said heating action

Methodology Applied
Scientific EffectDielectric heating: Dielectric Heating

Data Source

PatentEP2830805B1Method for processing a modular hybrid component
Publication Date: 2019.07.31 ANSALDO ENERGIA IP UK LTD
  • EP2830805B1 patent drawingFigure 1a~1d

AI summary

The invention relates to a method for processing a modular hybrid component (10) comprising a first part (11) made of a first material and a second part (12) made of a second material, which is different from said first material with regard to its electromagnetic and/or thermal properties, characterized in that said modular hybrid component (10) is exposed to an alternating electromagnetic field, whereby both parts (11, 12) are heated up differently, and that a brazing or soldering joint (13) or field sensitive mineral cement between said first part (11) and said second part (12) is affected by said heating action.