FAST-Joined Turbine Vane Doublets for TBC Coverage and Low Leakage

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Gas turbine engine turbine vanes, especially doublets, face challenges in achieving good thermal barrier coating (TBC) coverage without increasing leakage or costs, as singlets provide better TBC but are costly and prone to leakage, while doublets have poor TBC coverage but reduced leakage and lower costs.

Innovation Solution

A method involving casting, machining, and thermal barrier coating of turbine vanes followed by field-assisted sintering technology (FAST) processing to join turbine vane singlets into doublets, allowing for improved TBC coverage and reduced leakage without increased costs, by forming metallurgical bonds at lower temperatures using high amperage pulsed direct current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If turbine vanes are provided as singlets, then thermal barrier coating coverage is improved, but leakage increases and costs increase

Engineering Contradiction:
ImproveTBC coverageVSAvoidleakage
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent combines multiple turbine vane singlets into a doublet configuration by joining them together, thereby maintaining the excellent TBC coverage benefits of singlets while achieving the leakage reduction and cost benefits associated with doublets. The joining process merges two separate vanes into a unified structure that captures both advantages.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If turbine vanes are provided as doublets, then leakage is reduced and costs are reduced, but thermal barrier coating coverage deteriorates

Engineering Contradiction:
ImproveleakageVSAvoidTBC coverage
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies thermal barrier coating to each turbine vane singlet before joining them into a doublet. This preliminary coating action ensures that all surfaces, including those that would later be in contact during joining, receive complete and high-quality TBC coverage. The coating is applied to the singlet configuration where line-of-sight access is available, then the vanes are joined while maintaining this coating integrity.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If traditional joining methods are used to form doublets, then manufacturing simplicity is maintained, but thermal barrier coating coverage deteriorates due to hidden line-of-sight surfaces

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidTBC coverage
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent reverses the conventional sequence by coating the turbine vanes before joining them, rather than coating after joining. This preliminary coating action eliminates the hidden line-of-sight surface problem entirely, as all surfaces are accessible during the singlet configuration. The method maintains manufacturing simplicity by using standard coating and joining processes in a re sequenced workflow.

Inventive Principle:
Principle #10Preliminary action

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 forms turbine vane doublets with reduced leakage and improved TBC coverage, utilizing high-strength alloys that withstand high temperatures and stresses, while maintaining cost-effectiveness by employing FAST processing to consolidate powder materials into dense compacts with fine feature retention.

Implementation Method 1

executing field assisted sintering technology (FAST) processing to join the first and second turbine vanes

Methodology Applied
Scientific EffectField assisted sintering technology (FAST): Sintering

Implementation Method 2

forming metallurgical bonds at lower temperatures using high amperage pulsed direct current

Methodology Applied
Scientific EffectHigh amperage pulsed direct current: Joule Heating

Implementation Method 3

coating each of the first and second turbine vanes with thermal barrier coating (TBC)

Methodology Applied
Scientific EffectThermal barrier coating: Thermal Insulation

Data Source

PatentEP4105444A1Joining individual turbine vanes with field assisted sintering technology (FAST)
Publication Date: 2022.12.21 RTX CORP
  • EP4105444A1 patent drawingFigure 1
  • EP4105444A1 patent drawingFigure 2~3
  • EP4105444A1 patent drawingFigure 4

AI summary

A method of joining first and second turbine vanes (210, 220) is provided. The method includes casting and machining each of the first and second turbine vanes (210, 220), coating each of the first and second turbine vanes (210, 220) with thermal barrier coating (TBC) (214, 224) and executing field assisted sintering technology (FAST) processing to join the first and second turbine vanes (210, 220).