Rounded Blade Stub Geometry for Clean Orbital Friction Welding
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Solution Overview
Problem
Existing methods for orbital friction welding of turbomachine blades to rotor disks often result in structural defects and material health issues due to inadequate junction design, leading to contaminants and incomplete welds.
Innovation Solution
A method for sizing the junction section between blades and stubs with rounded contours at the ends, having an average radius of at least twice the eccentric, to ensure optimal contact and thermal homogeneity during welding, thereby preventing material recirculation and ensuring a robust, contaminant-free weld.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional stump design with straight edges is used for orbital welding, then manufacturing is simpler, but weld quality deteriorates due to material recirculation and contaminants
Solution Approach 1:
The invention applies curvature by replacing straight edges with rounded contours at the ends of the stump. The rounded contour has a radius R ≥ e (eccentricity), creating a curved geometry that prevents material recirculation during orbital welding. This curvature ensures that material flows in one direction only, eliminating contaminants and improving weld quality without significantly complicating the manufacturing process.
2Temperature
If orbital welding is performed with conventional stump geometry, then welding speed is maintained, but thermal homogeneity deteriorates leading to structural defects
Solution Approach 1:
The invention changes the geometric parameter of the stump end from straight to rounded with radius R ≥ e. This parameter change optimizes the contact surface evolution during orbital welding, ensuring uniform heat distribution and thermal homogeneity throughout the weld zone. The rounded geometry maintains appropriate contact pressure distribution, allowing high welding speed to be sustained while achieving homogeneous heating and preventing structural defects.
3Object-generated harmful factors
If straight-edged stumps are used, then material consumption is easier to control, but contaminant formation increases during welding
Solution Approach 1:
The rounded contour with radius R ≥ e creates a geometry where material is pushed outward in a controlled manner during orbital welding. The curvature prevents material from recirculating back into the weld zone, thereby eliminating contaminant formation. The gradual transition of the rounded edge maintains stable material flow and consumption, preserving manufacturing precision while producing clean, contaminant-free welds.
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 the quality of the weld by maintaining constant material consumption and preventing contaminant recirculation, resulting in a stronger, more robust, and structurally sound joint with improved thermal homogeneity.
Implementation Method 1
orbital friction welding is a welding process in which the parts to be joined are brought into contact under stress and welded by a circular motion generally defined by an eccentric, and accompanied by a uniform tangential speed, so as to generate friction and homogeneous heating at a weld junction between the two parts
Implementation Method 2
orbital friction welding of blades to a stub of a rotor disc, in which the stump has a rounded contour at each of its ends, having an average radius, over a sector of at least 120°, of at least twice the eccentric e
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention proposes a method for dimensioning a junction section (S) (10) by orbital friction welding with an eccentric e, between a blade (4) and a stub (6) of a bladed disk for turbomachine, in which the dimensioned section (S) has a rounded contour (12, 13) at one or two ends of said section along a chord (C) of the blades, each corresponding to a leading edge (4.2) or a trailing edge (4.3) of said blades, said or said rounded contours having on a sector (N, M) of at least 120° an average radius of at least twice the eccentric e.