Friction Stir Welding Tool with Chamfered Shoulder and Spiral Grooves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Friction stir welding techniques are not effective or efficient for welding two metal pieces with significantly different thicknesses and often result in burrs on the weld surface, especially when high rotational and translational speeds are used.
Innovation Solution
A friction stir welding tool with a chamfered shoulder and optionally chamfered sidewalls of a spiral pattern on the distal face, which reduces the formation of burrs and enhances heat transfer, allowing for higher rotational speeds and translational speeds while maintaining a smooth weld finish.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high rotational speeds and high translational speeds are used in friction stir welding, then productivity is improved, but burr formation increases and weld quality deteriorates
Solution Approach 1:
The patent modifies the geometric parameters of the friction stir welding tool, specifically introducing a chamfered shoulder design with a defined chamfer angle (α) and spiral groove patterns. These parameter changes alter the material flow dynamics during welding, enabling high-speed operation without burr formation by controlling the plasticized material's movement and preventing it from accumulating at the weld surface.
Solution Approach 2:
The patent incorporates spiral grooves with specific curvature radii (R1, R2, R3) in the distal face of the tool. These curved geometric features guide the material flow in a controlled manner during the welding process, preventing material buildup and burr formation even at high rotational and translational speeds, thus maintaining weld quality while improving productivity.
2Productivity
If high rotational speeds are used in friction stir welding, then productivity is improved, but burr formation increases
Solution Approach 1:
The chamfered shoulder geometry with specific chamfer angle and the spiral groove configuration change the material flow parameters during welding. This prevents material from being forced upward and forming burrs, even when the tool rotates at high speeds, thus enabling high productivity without the harmful effect of burr formation.
Solution Approach 2:
The spiral grooves with optimized curvature radii create a controlled material flow path that prevents material accumulation at the weld surface during high-speed rotation. The curved geometry guides the plasticized material smoothly, eliminating the conditions that lead to burr formation while maintaining high rotational speeds for improved productivity.
3Manufacturing precision
If conventional friction stir welding tools are used, then manufacturing simplicity is maintained, but weld quality and tool lifetime are reduced
Solution Approach 1:
The patent introduces specific geometric parameters including chamfer angle (α), spiral groove angles (β1, β2), and curvature radii (R1, R2, R3) to optimize material flow and weld quality. These parameter modifications, while adding some complexity to the tool design, dramatically improve weld surface quality and reduce burr formation, justifying the increased manufacturing complexity.
Solution Approach 2:
The spiral grooves with specific curvature radii create optimized material flow paths that significantly improve weld quality and reduce burr formation. The curved geometric features, while adding manufacturing complexity, enable controlled material movement that conventional straight or simple grooves cannot achieve, resulting in superior weld quality and tool performance.
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 tool effectively prevents burr formation and increases the strength and durability of the weld, enabling the use of higher operating parameters without compromising the quality of the weld, thus improving the tool's lifetime and weld quality.
Implementation Method 1
Mechanical stirring and frictional heat introduced into the material at the joint by the rotating tool
Implementation Method 2
Friction stir welding is a method useful for joining two or more separate metal pieces by way of a strong, permanent metallic bond (i.e., weld)
Implementation Method 3
enhances heat transfer, allowing for higher rotational speeds and translational speeds
Data Source
AI summary
Described are tools useful to produce a friction stir weld, methods of forming a friction stir weld, and assemblies such as electronic devices that include a friction stir weld.