Bladed Disc 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 stump design, which cannot be applied to orbital welding and lead to contaminated welds.
Innovation Solution
A method for sizing the junction section between blades and stubs, ensuring a ratio of maximum to minimum average ray length is less than or equal to 2, with specific dimensions and widening of the section to optimize orbital welding, using a ray tracing technique for precise characterization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional stump design is used for orbital welding, then the welding process can be completed, but the weld junction presents structural defects and material health defects
Solution Approach 1:
The stump is designed with a specific geometric configuration where the ratio of maximum to minimum average ray lengths is between 0.8 and 1.2. This local geometric optimization at the welding interface ensures uniform material flow and eliminates dead zones where contaminants could accumulate, directly resolving the weld quality issues while maintaining manufacturability
Solution Approach 2:
The invention changes the geometric parameters of the stump by defining a specific ratio range (0.8-1.2) for maximum to minimum average ray lengths. This parameter optimization transforms the stump geometry to achieve contaminant-free welds while remaining compatible with standard orbital welding processes
2Reliability
If the stump geometry does not meet the ray length ratio criterion, then manufacturing is simpler, but material recirculation and contaminant accumulation occur in the weld zone
Solution Approach 1:
The invention replaces complex mechanical trial-and-error stump design with a mathematical ray tracing approach. By calculating average ray lengths from peripheral points and enforcing a 0.8-1.2 ratio, the method systematically determines optimal stump geometry, eliminating contaminant accumulation zones while providing clear manufacturing guidelines
Solution Approach 2:
The stump geometry is pre-optimized using ray tracing calculations before the welding process begins. By establishing the 0.8-1.2 ray length ratio criterion in advance, the design prevents material recirculation and contaminant trapping from occurring, ensuring weld health before manufacturing commences
3Productivity
If orbital welding is performed without proper stump dimensioning, then the process speed is maintained, but structural defects appear in the weld junction
Solution Approach 1:
The invention optimizes the stump geometric parameters by enforcing a 0.8-1.2 ratio between maximum and minimum average ray lengths. This parameter change ensures uniform material flow during orbital welding, eliminating structural defects while maintaining the high productivity advantages of orbital welding processes
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 guarantees a healthy, contaminant-free weld with improved structural quality and reduced material recirculation, enhancing the robustness and homogeneity of the weld, while minimizing the presence of contaminants.
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
the relative movement between the two interfaces is continuous thanks to the circular friction movement, which provides better thermal homogeneity
Data Source
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AI summary
The invention proposes a method for dimensioning a junction section (S) (10) by orbital friction welding between a blade (4) and a stub (6) of a bladed disk for a turbomachine, remarkable in that the section is dimensioned so that the ratio between an average length of radii extending totally in the section from a point at the periphery of said section and sweeping said section, where said average length of radii is a maximum average length zmax, and an average length of radii extending totally in the section from another point at the periphery of said section and sweeping said section, where said average length is a minimum average length zmin, is less than or equal to 2.