Fan Blade Leading Edge Sheath Forming With Low Material Waste
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Solution Overview
Problem
Current methods for manufacturing protective sheaths for fan blade leading edges in gas turbine engines are inefficient, time-consuming, and costly, often requiring excessive input material and discarding significant amounts, while struggling to produce dimensionally accurate sheaths with the desired aerodynamic contours.
Innovation Solution
A method involving superplastic forming and cold or warm forming processes to shape a preform plate into a protective sheath intermediate, which is then shaped to match the fan blade leading edge contour using a mandrel, minimizing material waste and tooling costs, and ensuring an air-tight fit with the fan blade.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional machining or EDM is used to shape the ID slot and leading edge nose from a larger block of input stock material, then the sheath can be manufactured with the desired shape, but a large amount of input material is discarded and the process is time-consuming and costly
Solution Approach 1:
The patent applies superplastic forming to change the physical state and formability parameters of the titanium alloy sheet, enabling it to be shaped into complex three-dimensional contours that match the fan blade leading edge. This process transforms the material from a flat sheet into a precisely contoured sheath with minimal material waste, resolving the contradiction between achieving precise shapes and minimizing material loss
Solution Approach 2:
The patent replaces conventional mechanical machining and EDM processes with a superplastic forming process that uses controlled thermal and mechanical fields to shape the material. This substitution eliminates the need for subtractive machining that generates significant waste, while still achieving the required dimensional accuracy and complex geometries
2Manufacturing precision
If conventional machining or EDM is used to shape the sheath, then the desired shape can be achieved, but the manufacturing process requires multiple tools and time-consuming steps
Solution Approach 1:
The patent combines multiple shaping operations into a single superplastic forming process. The preform plate is designed with features that will become the ID slot and leading edge nose, and all these features are formed simultaneously in one forming operation rather than through multiple sequential machining steps, significantly improving productivity
Solution Approach 2:
The patent performs preliminary shaping of the sheath into a preform plate configuration before the final forming operation. This preform plate is specifically designed with geometric features that facilitate the subsequent superplastic forming process, allowing the complex final shape to be achieved more efficiently. The preliminary action of creating the preform plate with appropriate geometry enables the final forming to proceed with fewer steps and higher productivity
3Reliability
If the ID slot and leading edge nose are shaped to match the fan blade leading edge contour, then an air-tight seal and aerodynamic performance are improved, but the manufacturing process becomes more difficult and expensive
Solution Approach 1:
The patent utilizes superplastic forming parameters (temperature, strain rate, pressure) to enable the titanium alloy to conform precisely to the complex fan blade leading edge contour. This parameter change allows the material to flow and adapt to the desired geometry, achieving the air-tight seal and aerodynamic contours that would be difficult to obtain through conventional machining
Solution Approach 2:
The patent introduces a mandrel as an intermediary tool that defines the target geometry of the fan blade leading edge. The preform plate is formed over this mandrel, allowing the sheath to automatically conform to the complex contours required for the air-tight seal and aerodynamic performance. The mandrel serves as a physical template that simplifies the manufacturing of complex shapes
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
This approach reduces material waste, lowers production costs, and enables the efficient manufacture of protective sheaths with precise aerodynamic contours, enhancing the structural integrity and aerodynamic performance of fan blades.
Implementation Method 1
A method involving superplastic forming and cold or warm forming processes to shape a preform plate into a protective sheath intermediate
Implementation Method 2
A method involving superplastic forming and cold or warm forming processes to shape a preform plate into a protective sheath intermediate
Data Source
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AI summary
A method for manufacturing a protective sheath for a fan blade leading edge is described. The method may comprise generating a preform plate from a stock plate wherein the preform plate has a flattened surface and an inclined surface having a spike flanked by a first side and a second side. The method may further comprise bending the first side and the second side away from the spike to generate a sheath intermediate followed by generating the protective sheath from the sheath intermediate by shaping an outer surface and an inner surface of the sheath intermediate to match the contour of the fan blade leading edge.