Liquid-Cooling Jacket Friction Stir Welding for Defect-Free Joints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in manufacturing liquid-cooling jackets involves joining different aluminum alloys using friction stir welding, where the harder jacket body material creates resistance issues, leading to cavity defects and reduced joint strength, and existing quality control methods cannot accurately determine the rotary tool's passed position.
Innovation Solution
A method involving a rotary tool with a shoulder portion and a stirring pin, where the jacket body and sealing body are prepared with specific stepped portions and thicknesses, allowing for controlled friction stirring and the formation of a coarse portion for flaw detection to ensure joint strength and track the tool's path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If friction stir welding is performed with a conventional rotary tool on different aluminum alloys, then the joining process can be completed, but the material resistance from the harder jacket body causes cavity defects and reduced joint strength
Solution Approach 1:
The invention changes the geometric parameters of the stirring pin by providing an inclined outer circumferential face with a specific inclination angle (10° to 45°). This parameter modification allows the stirring pin to effectively stir harder aluminum alloy materials (4000 series) by reducing material resistance, thereby preventing cavity defects and improving joint strength when joining dissimilar aluminum alloys.
Solution Approach 2:
The stirring pin is designed with a localized inclined outer circumferential face rather than a uniform cylindrical shape. This local quality change concentrates the stirring action and reduces material resistance at the critical interface between the stirring pin and the harder jacket body material, preventing cavity formation while maintaining effective material mixing.
2Stability of the object's composition
If conventional friction stir welding is used to join different aluminum alloys, then the joining process can be completed, but it is difficult to stir different kinds of materials with good balance
Solution Approach 1:
The inclined outer circumferential face of the stirring pin modifies the material flow characteristics during friction stir welding. The inclination angle (10° to 45°) creates a more balanced stirring action that effectively mixes dissimilar aluminum alloy materials (1000 series and 4000 series) with appropriate proportions, achieving stable material composition in the joint region and preventing weak joints.
3Measurement precision
If ultrasonic flaw detection is performed for quality control, then the presence or absence of poor joining can be detected, but it is not possible to know where the rotary tool has passed
Solution Approach 1:
The inclined outer circumferential face of the stirring pin creates a distinctive coarse portion (mixing zone) with a specific width (0.5 mm to 2.0 mm) that serves as an intermediary marker. This coarse portion, formed by the unique stirring action of the inclined surface, can be detected by ultrasonic flaw detection equipment, thereby providing tool path information that was previously unavailable while maintaining flaw detection accuracy.
4Ease of manufacture
If a conventional cylindrical stirring pin is used, then the friction stir welding process can be completed, but cavity defects occur due to high material resistance from the harder jacket body
Solution Approach 1:
The stirring pin is designed with an inclined outer circumferential face (inclination angle 10° to 45°) instead of a conventional cylindrical shape. This geometric parameter change reduces material resistance when stirring harder aluminum alloy (4000 series) jacket body materials, preventing cavity defects while maintaining ease of manufacturing the welding joint.
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 method effectively joins different aluminum alloys with improved joint strength and allows for accurate quality control by detecting the rotary tool's passed position, reducing metal mixing and preventing metal shortages in the joined portion.
Implementation Method 1
friction stir welding
Implementation Method 2
frictional heat between the sealing body and the stirring pin
Implementation Method 3
plasticized region formed by joining
Data Source
AI summary
The present invention includes: a primary joining process in which a coarse portion having a predetermined width is formed in the vicinity of a step side face within a plasticized region while the rotary tool is being moved one round along a first butted portion to perform friction stirring in a state that a tip of a stirring pin of a rotary tool being rotated is inserted to the same depth as or slightly deeper than a step bottom face and a bottom face of a shoulder portion is in contact with a front face of a sealing body and the stirring pin is slightly in contact with at least an upper portion of a jacket body; and an inspection process in which a passed position of the stirring pin is specified by performing, after the primary joining process, a flaw detection to detect the coarse portion.