Inclined Weld Interface Geometry for Gas Turbine Rotor Discs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inertia friction welding in gas turbine rotor discs leads to reduced mechanical performance, increased oxidation damage, high residual stresses, and reduced fatigue life due to weld geometry and material properties.
Innovation Solution
A rotary friction welding process where the weld interfaces are inclined from the radial direction, allowing the welds to be formed at the radially inner side of the rim portion, reducing exposure to high temperatures and stresses, and incorporating convexities to control heat flow and expulsion of material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If inertia friction welding is used to join rotor discs, then the workpieces can be welded together by converting mechanical energy to heat energy, but the weld geometry and material properties lead to reduced mechanical performance, increased oxidation damage, high residual stresses, and reduced fatigue life
Solution Approach 1:
The patent changes the geometric parameters of the weld interface by introducing an inclination angle relative to the radial direction. This parameter change transforms the weld interface from a conventional radial orientation to an inclined orientation, which fundamentally alters the stress distribution, heat flow patterns, and material flow characteristics during welding and service, thereby improving mechanical performance and reducing the harmful effects of conventional inertia welding
2Reliability
If the weld interfaces are positioned at the radially inner side of the rim portion, then exposure to high temperatures and stresses is reduced, but the welding process complexity increases due to the need for inclined surfaces and convexities
Solution Approach 1:
The patent introduces asymmetry in the weld interface design by inclining the weld surfaces at a specific angle relative to the radial direction. This asymmetric geometry is combined with convexities on the weld surfaces, creating a non-conventional interface that strategically positions the weld at the radially inner side where it experiences reduced thermal and mechanical stresses, thereby improving reliability despite increased geometric complexity
Solution Approach 2:
The patent adds a new dimensional aspect to the weld interface by introducing an inclination angle in addition to the conventional radial positioning. This creates a three-dimensional weld geometry with both radial and axial components, allowing the weld to be positioned optimally within the component structure to minimize exposure to harsh operating conditions
3Manufacturing precision
If convexities are incorporated to control heat flow and material expulsion, then weld quality improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies local quality by introducing convexities at specific locations on the weld interface rather than uniformly across the entire surface. These localized geometric features are strategically positioned to control heat flow and material expulsion at critical areas during the welding process, thereby improving overall weld quality while managing manufacturing complexity through targeted rather than universal modifications
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 process increases the service life of the assembly, reduces inspection intervals, and lowers overall costs by mitigating the issues associated with inertia welding, while maintaining or improving mechanical performance.
Implementation Method 1
rotating one of the outer and front inner workpieces about the axis relative to the other aligned workpiece, engaging the aligned workpieces at the front first and second weld surfaces such that the rotation raises the temperature at the front weld surfaces to create a front weld interface
Data Source
AI summary
The present disclosure provides a rotary friction welding process including: providing an outer axisymmetric workpiece having a front first annular weld surface at a radially inward extent and a rear first annular weld surface at a radially inward extent; providing a front inner axisymmetric workpiece, the front inner workpiece having a front second annular weld surface at a radially outward extent of the front inner workpiece; providing a rear inner axisymmetric workpiece, the rear inner workpiece having a rear second annular weld surface at a radially outward extent of the rear inner workpiece; and rotary welding the workpieces together.