Additive Blade Sheath Fabrication for Uniform Microstructure
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Solution Overview
Problem
Existing methods for producing blade sheaths for fan blades in gas turbine engines are costly, have low productivity, and result in microstructural anomalies, limiting dimensional accuracy and surface finish.
Innovation Solution
A method involving additive manufacturing to form upper and lower sleeves with a central portion bonded to them, using techniques like wire arc additive manufacturing to create a uniform microstructure and smooth internal surfaces, and applying a protective coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If subtractive methods such as milling and machining techniques are used to produce blade sheaths, then the sheaths can be manufactured with traditional processes, but the cost is high, productivity rates are low, and lead times are long
Solution Approach 1:
The patent inverts the traditional subtractive manufacturing approach by using additive manufacturing (wire arc additive manufacturing) to build the sheath material layer by layer. Instead of removing material from a blank, the process deposits titanium material to form the sheath, central portion, and reinforcement features directly, achieving higher productivity and reduced lead times while maintaining manufacturing capability
Solution Approach 2:
The patent changes the fundamental manufacturing parameter from subtractive removal to additive deposition. By using wire arc additive manufacturing with titanium wire and controlled heat input, the process achieves complex geometries and reinforced features that would be difficult or impossible to create with traditional machining, while significantly improving production efficiency
2Ease of manufacture
If subtractive methods are used to produce blade sheaths, then traditional manufacturing can be maintained, but dimensional accuracy and surface finish are limited
Solution Approach 1:
The patent replaces the mechanical cutting and machining system with a thermal deposition system. Wire arc additive manufacturing uses controlled arc heating to melt and deposit titanium material, allowing for precise dimensional control and superior surface finish compared to subtractive methods. The process can achieve complex curved geometries and tight tolerances that are difficult to obtain through machining
Solution Approach 2:
By changing from mechanical removal to thermal deposition, the patent achieves better dimensional accuracy and surface finish. The additive process allows for controlled layer-by-layer building with precise heat input management, resulting in smoother surfaces and more accurate geometries without the tool marks and dimensional limitations inherent in subtractive manufacturing
3Ease of manufacture
If traditional manufacturing techniques are used for blade sheaths, then conventional processes can be employed, but microstructural anomalies are left in the sheath
Solution Approach 1:
The patent replaces mechanical machining processes with wire arc additive manufacturing, which deposits material in a controlled manner that produces a more uniform microstructure. The gradual layer-by-layer deposition with controlled heat input avoids the stress concentrations and microstructural disruptions caused by machining operations, resulting in superior material integrity and fewer anomalies
Solution Approach 2:
The patent creates a composite structure by depositing titanium material that forms a central portion with reinforcement features integrated into the sheath. The additive manufacturing process allows for controlled material deposition that can incorporate reinforcement elements and create a unified microstructure throughout the sheath, improving overall material integrity and eliminating weak points that might arise from traditional manufacturing joints or machining-induced stresses
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 enhances productivity, reduces costs, and improves dimensional accuracy and surface finish while providing enhanced protection against impact and erosion.
Implementation Method 1
The central portion is formed by depositing a first layer of titanium material on the upper sleeve and the lower sleeve. The material may be deposited using wire arc additive manufacturing.
Implementation Method 2
The central portion is formed by depositing a first layer of titanium material on the upper sleeve and the lower sleeve
Implementation Method 3
The central portion may be formed by applying a heat source to a wire comprising titanium
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A method of making a sheath for an airfoil may include the steps of forming an upper sleeve (172) and a lower sleeve (174), and forming a central portion (176) bonded to the upper sleeve (172) and the lower sleeve. The central portion (176) may be formed by depositing a material on the upper sleeve (172) and the lower sleeve. A portion of the material may be removed from at least one of the central portion (176), the upper sleeve (172), or the lower sleeve. The sheath may include a first flank, a central portion (176) bonded to the first flank, and a second flank bonded to the central portion (176). The central portion (176) may have a substantially uniform microstructure resulting from additive manufacturing.