Textured Stator Vane Braze Joints to Prevent Overflow Cracking

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Solution Overview

Problem

Existing gas turbine engines face challenges in securing vanes to shrouds via braze joints, particularly due to issues like braze material overflow and cracking, which can lead to reduced aerodynamic performance and joint failure.

Innovation Solution

The implementation of texturing on the periphery of mounting feet, such as knurling, grooves, or abrasions, to trap and accommodate braze material, preventing overflow and minimizing braze material on high-stress fillet transitions, thereby enhancing joint integrity and aerodynamic performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If braze material is applied to join mounting feet to shrouds, then joint strength is improved, but braze material may overflow onto fillet transitions causing cracking and delamination

Engineering Contradiction:

Improvejoint strengthVSAvoidjoint reliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The mounting foot periphery is textured only in specific locations where braze material contact occurs, while leaving other areas smooth. This localized texturing provides braze accommodation exactly where needed without affecting aerodynamic surfaces or fillet transitions, resolving the contradiction between joint strength and reliability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The texturing acts as an intermediary feature between the mounting foot and braze material. It provides a controlled interface that accommodates braze material volume changes and prevents direct contact between excess braze and critical fillet areas, thereby maintaining both joint strength and reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If braze material is applied to secure vanes to shrouds, then mounting reliability is improved, but aerodynamic performance deteriorates due to overflow onto critical surfaces

Engineering Contradiction:

Improvemounting reliabilityVSAvoidaerodynamic performance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

Texturing is applied only to the periphery of mounting feet where braze material contact occurs, while aerodynamic surfaces remain smooth. This localized approach ensures reliable mounting through braze accommodation without compromising aerodynamic performance on critical surfaces.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The texturing converts the potentially harmful effect of braze material overflow into a beneficial feature by providing designated accommodation zones. Excess braze material is channeled into the textured regions rather than contaminating aerodynamic surfaces, transforming a reliability improvement mechanism into one that also preserves aerodynamic performance.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If smooth mounting foot surfaces are used, then aerodynamic performance is maintained, but braze material overflow and joint failure increase

Engineering Contradiction:

Improveaerodynamic performanceVSAvoidjoint reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The mounting foot surface is differentially treated: textured at the periphery for braze accommodation and smooth in other areas for aerodynamic performance. This resolves the contradiction by providing both braze joint reliability and aerodynamic efficiency in different locations on the same component.

Inventive Principle:

Principle #3Local quality

4Reliability

If texturing is added to mounting feet, then braze material accommodation is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvebraze joint reliabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The surface topology parameter of the mounting foot is changed by adding texturing features. This single parameter modification enables braze material accommodation and prevents overflow, achieving improved joint reliability without fundamentally changing the manufacturing process or adding significant complexity.

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 texturing of mounting feet surfaces improves joint reliability by reducing failure modes like cracking and delamination, while maintaining or improving aerodynamic efficiency by limiting braze material overflow onto critical areas.

Implementation Method 1

The mounting foot has a periphery with texturing. Braze material joins the texturing to a surface of the associated aperture.

Methodology Applied

Scientific EffectSurface roughness texturing:

Implementation Method 2

Each of the mounting feet has a circumscribing peripheral surface extending through an associated shroud aperture having surface. The peripheral surface is secured to the associated shroud via a braze joint.

Methodology Applied

Scientific EffectBrazing: Brazing

Data Source

PatentUS12601273B2Stator vane braze joints

Publication Date: 2026.04.14 PRATT & WHITNEY CANADA CORP

AI summary

A stator stage has: at least a first shroud being an inner diameter shroud or an outer diameter shroud; and vanes mounted to the first shroud. Each vane has a mounting foot received in an aperture in the first shroud and brazed thereto. The mounting foot has a periphery with texturing. Braze material joins the texturing to a surface of the associated aperture.