Friction Stir Welding Dissimilar Metal Thicknesses
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Solution Overview
Problem
Friction stir welding techniques are not effective for welding metal components with significantly different thicknesses and are prone to wormhole defects, which can compromise the hermetic seal in electronic devices.
Innovation Solution
The use of precisely formed metal components with complementary surfaces and edges to minimize air pockets, combined with controlled friction stir welding methods to prevent wormhole defects, ensures a reliable hermetic seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If friction stir welding is used to join metal components with significantly different thicknesses, then welding capability is extended, but weld quality deteriorates due to wormhole defects
Solution Approach 1:
The patent applies local quality by creating a tapered transition zone in the thicker component where the thickness gradually changes from the base thickness to a reduced thickness at the joint region. This localized geometric modification allows the friction stir welding tool to effectively join components of significantly different thicknesses by providing a progressive thickness transition that prevents wormhole defect formation, thereby maintaining weld quality while extending welding capability.
2Ease of manufacture
If friction stir welding is performed on thin metal components, then joining is achieved, but weld reliability deteriorates due to wormhole defects
Solution Approach 1:
The patent applies preliminary action by pre-forming the metal components with specific geometric features (tapered transitions, stepped configurations, or contoured surfaces) before the friction stir welding process. These pre-formed geometric characteristics are designed to control material flow and prevent vacuum pocket formation during welding, thereby ensuring hermetic seal integrity when joining thin metal components without compromising reliability.
3Device complexity
If conventional friction stir welding is used, then welding process is simple, but weld quality deteriorates due to wormhole defects from inadequate material mixing
Solution Approach 1:
The patent applies parameter changes by modifying the geometric parameters of the workpiece (creating tapered transitions, stepped configurations, or contoured surfaces) rather than changing the welding tool or process parameters. This approach maintains the simplicity of the friction stir welding process while improving material mixing and preventing wormhole defects, thereby achieving high manufacturing precision through workpiece geometry optimization.
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 achieves a high-quality friction stir weld with reduced likelihood of wormhole defects, enabling a hermetic seal that maintains a low-density atmosphere within electronic devices, such as hard disk drives, with minimal leakage.
Implementation Method 1
Friction stir welding is a technique that is known to be useful in various applications for welding metals
Implementation Method 2
Friction stir welding techniques can be most effectively and reliably used for welding together two metal components
Implementation Method 3
The feature of 'stirring' the materials of the friction stir weld during weld formation, which is an implicit feature of a friction stir welding process
Data Source
AI summary
Described are devices and assemblies (e.g., precursors to a devices) that include a friction stir weld or a joint useful for forming a friction stir weld, the devices containing two metal components that form the joint at which the friction stir weld can be produced, as well as methods for producing a devices, assembly, joints, or friction stir weld as described.