Nickel Alloy Welding Wire for Turbine Blade Crack Repair

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Solution Overview

Problem

Current methods for repairing nickel-based superalloy components, such as turbine blades, lack effective solutions for reliable and efficient crack repair, particularly in high-temperature applications, due to the expense and difficulty of replacing these components.

Innovation Solution

A nickel alloy welding wire with a specific composition (4.75-5.25 wt% Cr, 5.5-6.2 wt% Al, 5.6-6.2 wt% W, 8.0-8.3 wt% Ta, 1.7-2.1 wt% Mo, 9.5-10.5 wt% Co, 2.8-3.2 wt% Re, and balance Ni) is used to repair cracks in turbine engine components by heating the area to 1625-1675°F (885-913°C) and applying the wire, allowing the material to flow into the crack and solidify.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional welding methods are used to repair nickel-based superalloy components, then the repair process is complex and time-consuming, but the structural integrity and reliability of the repaired components are insufficient

Engineering Contradiction:
Improvestructural integrityVSAvoidrepair process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the chemical composition parameters of the welding wire by precisely controlling the content of alloying elements (Cr: 20-30%, Co: 5-15%, Mo: 3-10%, W: 5-15%, Al: 3-10%, Ta: 5-15%, Ni: 10-20%, and trace elements Re: 0.01-0.05%, B: 0.003-0.008%). This compositional parameter optimization enables the welding material to achieve better metallurgical compatibility with nickel-based superalloys, improving the reliability of repaired components while simplifying the repair process through direct welding without complex intermediate steps

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite welding wire material that combines multiple alloying elements in specific proportions. This composite composition provides synergistic effects where Cr and Mo enhance corrosion resistance, Co and W improve high-temperature strength, Al and Ta form protective oxide layers, and trace Re and B refine grain structure. The composite material approach achieves superior structural integrity while maintaining process simplicity

Inventive Principle:
Principle #40Composite materials

2Temperature

If existing welding wires are used for repairing nickel-based superalloy components, then the repair can be performed, but the high-temperature performance and oxidation resistance of the repaired areas are insufficient

Engineering Contradiction:
Improvehigh-temperature performanceVSAvoidoxidation resistance
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The invention optimizes temperature-related parameters through compositional design. The welding wire contains Al (3-10%) and Ta (5-15%) which form stable oxide layers at high temperatures, Cr (20-30%) and Mo (3-10%) that maintain solid solution strengthening at elevated temperatures, and trace Re (0.01-0.05%) that enhances creep resistance. These parameter optimizations ensure the repaired components maintain both high-temperature performance and oxidation resistance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies local quality enhancement by concentrating oxidation-resistant elements (Cr, Al, Ta) and high-temperature strength elements (Co, Mo, W, Re) in the welding wire composition. This creates a localized zone with superior properties at the repair site, where the welding material forms a metallurgically bonded region with enhanced oxidation resistance and high-temperature capability, while the base material retains its original properties

Inventive Principle:
Principle #3Local quality

3Reliability

If nickel-based superalloy components are replaced instead of repaired, then component reliability is maintained, but the cost and difficulty increase significantly

Engineering Contradiction:
Improvecomponent reliabilityVSAvoidrepair feasibility
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention applies the principle of using a specialized consumable welding wire (analogous to disposable material) to repair components. The welding wire is designed as a consumable material that is deposited during the welding process, filling defects and restoring component integrity. This approach is more economical than replacing entire expensive nickel-based superalloy components, while the controlled composition ensures the repaired areas achieve sufficient reliability for high-temperature applications

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The welding wire acts as an intermediary material between the damaged component and the desired repaired state. The specially formulated welding wire composition serves as a mediator that metallurgically bonds to the nickel-based superalloy substrate, transferring strength and oxidation resistance properties to the repaired area. This intermediary approach enables reliable repair without requiring complete component replacement

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

The nickel alloy welding wire provides improved material characteristics and effective crack repair for high-temperature applications, suitable for turbine blades and other components, with the ability to withstand stress relief heat treatments and maintain structural integrity.

Implementation Method 1

heating the workpiece to a temperature in the range of from about 1625 to 1675 degrees Fahrenheit (about 885°C to about 913°C)

Methodology Applied
Scientific EffectThermal heating: Heating

Implementation Method 2

maintaining the temperature until the repair material of the welding wire flows into and fills the crack

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP1835041B1Nickel alloy welding wire
Publication Date: 2010.09.15 UNITED TECH CORP

AI summary

In accordance with a first embodiment of the present invention, a nickel alloy welding wire is made from a material comprising from about 4.75 to 5.25 wt% chromium, from about 5.5 to 5.8 wt% aluminum, from about 5.6 to 6.2 wt% tungsten, from about 8.0 to 8.3 wt% tantalum, from about 1.7 to 2.1 wt% molybdenum, from about 9.5 to 10.5 wt% cobalt, from about 2.8 to 3.2 wt% rhenium, from about 0.07 to 0.30 wt% carbon, from about 0.02 to 0.04 wt% boron, from about 0.08 to 0.12 wt% zirconium, from about 0.08 to 0.12 wt% yttrium, from about 1.0 to 1.5 wt% hafnium, and the balance nickel. In a second embodiment of the present invention, a nickel alloy welding wire is made from a material comprising from about 4.75 to 5.25 wt% chromium, from about 5.5 to 5.8 wt% aluminum, from about 5.6 to 6.2 wt% tungsten, from about 8.0 to 9.0 wt% tantalum, from about 1.7 to 2.1 wt% molybdenum, from about 9.5 to 10.5 wt% cobalt, from about 2.8 to 3.2 wt% rhenium, from about 0.18 to 0.30 wt% carbon, from about 0.02 to 0.04 wt% boron, from about 0.08 to 0.12 wt% zirconium, from about 0.08 to 0.12 wt% yttrium, from about 1.0 to 1.5 wt% hafnium, and the balance nickel.