Turbine Component Repair Using Multi-Layer Braze Alloys
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Solution Overview
Problem
Current methods for repairing turbine engine components, such as diffusion brazing, are not effective for all types of damage and may not restore the original geometry and structural integrity of components like turbine nozzles and vane segments, especially in high-temperature environments, and are not cost-effective.
Innovation Solution
A method involving the application of a first braze alloy mixture followed by a second braze alloy mixture, both formulated with specific nickel-based alloys, and subjected to heat treatment and aging, to repair structural features like cracks and worn areas, restoring the component's original dimensions and properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If diffusion brazing process is used to repair turbine components, then cracks can be healed and material loss can be restored, but the process may not restore original geometry and structural integrity in high-temperature environments
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition parameters of the braze alloy, specifically incorporating reactive elements (rare earth metals like cerium, lanthanum, neodymium) and controlling the ratio of gamma prime formers to achieve optimal creep resistance and geometry restoration at high temperatures
Solution Approach 2:
The patent uses composite materials by creating a multi-component braze alloy system that combines nickel-based superalloy with reactive rare earth elements and gamma prime formers, resulting in a composite material that provides both crack healing and geometry restoration capabilities
2Temperature
If nickel-based superalloys are used for turbine blades and vanes to withstand high temperatures, then fuel efficiency increases, but the components become susceptible to corrosion, oxidation, and thermal fatigue
Solution Approach 1:
The patent applies local quality by creating a specialized braze alloy composition with reactive rare earth elements that locally enhances corrosion and oxidation resistance at the repair area, while maintaining the high-temperature properties of the base nickel-based superalloy component
Solution Approach 2:
The patent converts the susceptibility to corrosion and oxidation into a benefit by using reactive rare earth elements in the braze alloy that form protective oxide layers, transforming the harmful environmental interaction into a protective mechanism
3Ease of manufacture
If conventional braze alloy mixtures are used for repair, then the process is cost-effective, but the repair may not achieve sufficient creep resistance and mechanical property restoration
Solution Approach 1:
The patent applies parameter changes by optimizing the chemical composition parameters of the braze alloy, specifically controlling the content of gamma prime formers (aluminum, titanium) and reactive elements to achieve the desired balance between creep resistance, mechanical properties, and cost-effectiveness
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 heals cracks, restores geometry, and improves the mechanical properties of turbine engine components, providing a cost-effective solution that matches or exceeds the original component's performance.
Implementation Method 1
After a slurry coating of the braze alloy mixture is applied to a repair area on the turbine component and subjected to heat treatment in a vacuum furnace, the mixture melts and heals cracks and builds up material loss on the repair area
Implementation Method 2
subjected to heat treatment in a vacuum furnace
Implementation Method 3
heat treatment in a vacuum furnace
Data Source
AI summary
Methods are provided for repairing an engine component. In an embodiment, a method (400) includes forming (104) at least one layer of a first braze alloy mixture including about 40% by weight of a first base alloy material and about 60% by weight of a first braze alloy material, over a structural feature of the component. The first braze alloy material includes chromium, cobalt, tungsten, tantalum, aluminum, hafnium, carbon, boron, and a balance of nickel. A second braze alloy mixture is disposed (106) over the at least one layer of the first braze alloy mixture, the second braze alloy mixture including between about 50% and about 60% by weight of a second base alloy material, and between about 40% and about 50% by weight of a second braze alloy material. The component is then subjected (108) to heat treatment, and may be further subjected to machining, coating and final inspection.