Titanium Hollow Fan Blade Cover Welding With Low Distortion
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Solution Overview
Problem
The production of hollow titanium fan blades for gas turbine engines is time-consuming, complex, and expensive, often requiring costly protective environments and equipment.
Innovation Solution
Power beam welding, such as laser or electron beam welding, is used to attach a cover to the ribs of a twisted cavity-back fan blade, minimizing weld depth and heat input, reducing residual stress and blade distortion, and increasing structural integrity and fatigue life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional welding methods are used to attach the cover to the ribs, then the structural integrity can be achieved, but the production time increases and heat input causes residual stress and blade distortion
Solution Approach 1:
The patent replaces traditional arc welding (mechanical/thermal process) with electron beam welding (electromagnetic field process). The electron beam provides concentrated energy that melts and fuses the cover to the ribs with precise control, achieving strong joints faster than conventional methods while minimizing heat-affected zone and distortion.
Solution Approach 2:
The patent changes the welding parameters by using high energy density electron beam with controlled beam current, voltage, and scanning speed. This allows precise control of heat input, melting depth, and weld penetration, enabling quick welding cycles without compromising joint strength, thus reducing production time while maintaining structural integrity.
2Strength
If traditional welding methods are used to attach the cover to the ribs, then the cover can be secured, but heat input causes residual stress and blade distortion
Solution Approach 1:
The patent replaces traditional arc welding with electron beam welding, which provides more concentrated and controllable heat input. The electron beam can be precisely focused and moved, creating localized melting zones that minimize the overall heat-affected area, thereby reducing residual stress and thermal distortion while maintaining strong joints.
Solution Approach 2:
The patent uses intermittent or periodic electron beam welding passes with controlled dwell times. The beam can be pulsed or scanned in a controlled manner, allowing brief cooling intervals between passes that reduce cumulative heat buildup and residual stress, while still achieving adequate penetration and joint strength.
3Manufacturing precision
If hollow fan blade production uses complex protective environments, then manufacturing precision can be maintained, but production costs increase
Solution Approach 1:
The patent uses electron beam welding which can operate in vacuum environments. The vacuum chamber serves dual purposes: it protects the electron beam from atmospheric interference (ensuring welding precision) and simultaneously protects the titanium material from oxidation during welding. This integrated approach maintains manufacturing precision without requiring separate complex protective systems.
Solution Approach 2:
The patent employs a vacuum environment (inert atmosphere) during electron beam welding of titanium fan blades. The vacuum prevents oxidation of the titanium material and ensures stable electron beam operation, achieving high manufacturing precision. The vacuum system is more compact and easier to maintain than atmospheric shielding gas systems, reducing device complexity.
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 method reduces production time and costs while enhancing the structural integrity and fatigue life of the fan blades, minimizing stress concentrations and environmental constraints.
Implementation Method 1
Power beam welding, such as laser or electron beam welding, is used to attach a cover to the ribs of a twisted cavity-back fan blade
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
An airfoil including an airfoil body (112), a recessed portion (124) of a first depth in a first side (118) of the airfoil body (112), the recessed portion (124) including a plurality of pockets (126) of a second depth located within the recessed portion (124) and ribs (128) of the first depth located between the pockets (126), a cover configured to fit into the recessed portion (124) such that an interior surface of the cover engages the ribs (128) and an exterior surface of the cover is about flush with an exterior surface (122) of the first side (118) of the airfoil body (112), and a high energy beam weld configuration extending through the cover and into the ribs (128) and positioned to attach the cover to the ribs (128).