Hybrid Blade Tip Repair Using Welding and Solid-State Joining

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Solution Overview

Problem

Conventional turbine blade tip repair techniques lack durability and longevity, leading to reduced operational life and increased maintenance costs, as they cannot match the performance of newly manufactured parts.

Innovation Solution

A hybrid repair method involving gas tungsten arc welding to join a filler material with the airfoil, followed by solid-state joining of the blade tip body, using materials like single crystal metal alloys to create a robust and durable joint with precise surface flatness and smoothness, enhancing the structural integrity of the blade tip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional turbine blade tip repair techniques are used, then the repair process is simple and cost-effective, but the durability and operational life of the repaired blade is reduced

Engineering Contradiction:

Improvedurability of blade tip repairVSAvoidcomplexity of repair process

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The repair process is divided into distinct segments: defect removal, gas tungsten arc welding of filler material, solid-state joining of blade tip body, and surface finishing. Each segment addresses specific requirements, allowing the complex repair to be managed through systematic decomposition while achieving superior durability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The repair utilizes composite materials approach by combining different materials and joining methods: filler material welded to the airfoil, then a blade tip body made from potentially different material joined via solid-state process. This multi-material composite structure optimizes durability while managing the complexity through specialized material selection

Inventive Principle:

Principle #40Composite materials

2Duration of action of moving object

If multiple repairs are performed on blade tips, then the operational life is extended, but the durability decreases with each subsequent repair

Engineering Contradiction:

Improveoperational life of blade tipVSAvoiddurability after repeated repairs

Core Design Contradiction:

Duration of action of moving objectVSReliability

Solution Approach 1:

The invention changes the fundamental parameters of the repair process by transitioning from conventional single-method repair to a hybrid approach combining gas tungsten arc welding with solid-state joining. This parameter change in the repair methodology enables extended operational life while maintaining durability across multiple repair cycles

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The comprehensive defect removal and surface preparation performed before joining operations ensures that each repair starts with optimal conditions. By thoroughly preparing the mating surfaces and removing all defect remnants beforehand, the repair creates a clean foundation that maintains durability even when multiple repairs are performed over the blade's lifecycle

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If excess weld material is not removed, then the manufacturing process is simpler, but the flatness of the mating surface does not meet the threshold requirement

Engineering Contradiction:

Improveflatness of mating surfaceVSAvoidsimplicity of welding process

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Surface finishing operations are performed as a preliminary step before the solid-state joining process to ensure mating surfaces achieve the required flatness threshold. This preliminary preparation of surfaces ensures that the subsequent joining operation can proceed with precise alignment and meet dimensional specifications

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention replaces conventional mechanical machining with solid-state joining processes for the final connection. By using solid-state joining after achieving the required flatness through controlled material removal, the process achieves high precision without relying solely on extensive mechanical machining, balancing manufacturing precision with process efficiency

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 results in longer-lasting, more durable blade tip repairs that extend the operational life of gas turbine engines, providing a cost-effective alternative to replacing damaged blades.

Implementation Method 1

joining, via gas tungsten arc welding, a filler material to the airfoil to repair the defect

Methodology Applied

Scientific EffectGas tungsten arc welding: Welding

Implementation Method 2

joining the first mating surface of the airfoil to a second mating surface of a blade tip body via a solid-state joining process

Methodology Applied

Scientific EffectSolid-state joining: Diffusion Welding

Data Source

PatentUS11814979B1Systems and methods of hybrid blade tip repair

Publication Date: 2023.11.14 RTX CORP

AI summary

A method of repairing a tip for an airfoil is disclosed herein. In various embodiments, the method comprises: removing a portion of the airfoil that reduces a radial height of the airfoil and at least partially removes a defect of the airfoil; removing a remainder of the defect; joining, via gas tungsten arc welding, a filler material to the airfoil to repair the defect; and joining a first mating surface of the airfoil to a second mating surface of a blade tip body via a solid-state joining process.