Radiation Heat Shield for Uniform Brazing Temperature

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Solution Overview

Problem

Existing heat treating and brazing methods for gas turbine engine components face challenges in achieving uniform temperature distribution, leading to undesirable braze filler metal flow due to thermal mass differences between components, resulting in inefficiencies and increased energy costs.

Innovation Solution

A method involving a radiation heat shield formed from refractory metal sheets, configured to shield only the thinner portion of the assembly and create gaps to control heat flux, allowing for a more uniform heating rate and preventing premature melting of braze filler metal, which is applied adjacent to the joint and positioned to control both heating and cooling rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional heating methods are used without radiation heat shields, then heating speed is fast, but temperature distribution becomes non-uniform causing premature braze filler metal flow

Engineering Contradiction:
Improvetemperature distribution uniformityVSAvoidheating speed
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

A radiation heat shield made of refractory metal sheets is introduced as an intermediary component between the furnace heating elements and the assembly. The heat shield selectively shields the thinner portion from direct radiation, mediating the heat transfer to achieve uniform temperature distribution across components with different thermal masses, preventing premature braze filler metal flow while maintaining efficient heating speeds.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If the entire assembly is shielded from radiation, then temperature distribution becomes uniform, but overall heating efficiency decreases and energy consumption increases

Engineering Contradiction:
Improvetemperature distribution uniformityVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by stationary object

Solution Approach 1:

The radiation heat shield is configured to provide selective, localized shielding only to the thinner portion of the assembly that requires protection from excessive heating. The shield does not cover the entire assembly, allowing the thicker portions to receive full radiant heat exposure. This local quality approach achieves uniform temperature distribution while minimizing energy consumption by maintaining overall heating efficiency.

Inventive Principle:
Principle #3Local quality

3Productivity

If heating rate is increased to improve productivity, then throughput increases, but thermal mass differences cause non-uniform heating and defective braze joints

Engineering Contradiction:
ImprovethroughputVSAvoidbraze joint quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The radiation heat shield acts as a mediator that enables high heating rates to be used without compromising braze joint quality. By selectively shielding the thinner portion, the heat shield allows the furnace to operate at higher temperatures and faster heating rates needed for improved productivity, while preventing the thermal mass differences from causing non-uniform heating and defective joints.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This approach ensures a more uniform temperature distribution between components, preventing premature braze filler metal melting and improving the braze joint quality, reducing energy consumption and enhancing product throughput.

Implementation Method 1

A method for brazing an assembly in a furnace includes positioning a radiation heat shield to shield a first portion of the assembly from heating elements of the furnace

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 2

Heat is transferred by conduction from the metal members to the braze material to cause the braze material to melt

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2658675B1Heat treating and brazing of an object
Publication Date: 2018.05.02 ROLLS ROYCE CORP
  • EP2658675B1 patent drawingFigure 1~5
  • EP2658675B1 patent drawingFigure 5A~6

AI summary

One embodiment of the present invention is a unique method for brazing an assembly. Another embodiment is a unique method of heat treating an object. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for heat treating and/or brazing. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.