Laser Welded Blank Preparation for Low-Aluminum Flange Joints
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Solution Overview
Problem
Existing methods for manufacturing welded steel parts with aluminum pre-coatings face challenges such as aluminum dilution during laser beam welding, leading to reduced mechanical strength and toughness of the welded joint, and difficulties in precise positioning due to the darker appearance of sheets after peripheral metal layer removal.
Innovation Solution
A device and method involving simultaneous peripheral removal of the metal alloy layer by melting and vaporization using a laser beam, creating a clearance between the secondary faces of pre-coated steel sheets to prevent aluminum flow and enhance joint tracking precision during welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the aluminum-based pre-coating is removed by laser beam to avoid dilution during welding, then the aluminum content in the welded joint is reduced, but the sheets become darker making precise positioning difficult
Solution Approach 1:
The laser beam removes the aluminum-based pre-coating in advance before the welding operation, preventing aluminum dilution in the welded joint. This preliminary removal action ensures that the base metal surfaces are ready for welding with minimal aluminum content, directly addressing the manufacturing precision requirement.
Solution Approach 2:
The invention acknowledges that laser removal of the aluminum pre-coating changes the surface color of the sheets, making them darker. This color change creates a contrast that can be detected by optical sensors or cameras, allowing the positioning system to identify the edges and alignment of sheets despite the darkened appearance, thus solving the positioning precision difficulty.
2Strength
If the aluminum pre-coating is completely removed to prevent dilution, then the welded joint strength is improved, but the corrosion resistance may be compromised
Solution Approach 1:
The invention selectively removes only the aluminum-based pre-coating layer from the sheets before welding, extracting this layer to prevent aluminum dilution in the welded joint. By removing the pre-coating only at the welding zone, the base metal surfaces are exposed for strong welding while the rest of the sheets retain their original protective coatings, maintaining corrosion resistance in non-welded areas.
Solution Approach 2:
The laser beam applies localized treatment only to the specific regions where welding will occur, removing the aluminum pre-coating in these zones while leaving the pre-coating intact on the rest of the sheets. This local quality approach ensures that the welded joints have minimal aluminum content for high strength, while other areas maintain the protective aluminum coating for corrosion resistance.
3Productivity
If laser beam welding is used for flexibility and quality, then productivity is improved, but aluminum dilution occurs reducing joint toughness
Solution Approach 1:
The invention performs preliminary removal of the aluminum-based pre-coating using the laser beam before the welding operation. This preliminary action prevents aluminum from being diluted into the weld zone during laser beam welding, ensuring that the welded joint maintains high toughness and strength. The process maintains the productivity benefits of laser welding while eliminating the harmful aluminum dilution effect.
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 ensures minimal aluminum content in the welded joint (<0.3%) and improved precision in welding, resulting in welded blanks with enhanced mechanical properties and productivity, suitable for high-strength automotive components.
Implementation Method 1
simultaneous removal by fusion and vaporization of the layer of metal alloy 19, 20
Implementation Method 2
removal by fusion and vaporization of the layer of metal alloy 19, 20
Implementation Method 3
at least one source making it possible to obtain a laser beam 95 for welding the sheets 11, 12
Data Source
Figure 1~2
Figure 3
Figure 4~5D
AI summary
The invention relates to a device for manufacturing welded blanks comprising a supply device (91) for at least a first (11) and a second (12) steel sheets pre-coated with aluminum, or aluminum alloy, or aluminum-based alloy, a device for positioning said sheets (11, 12) so as to obtain a median plane between said sheets (11, 12), a clamping device for said sheets (11, 12), at least one source (96) for generating a laser beam (80) to remove, by melting and vaporization, the metallic layer of aluminum, or aluminum-based alloy, simultaneously on a peripheral area (61, 62) of said at least a first (11) and second (12) sheets, at least one guiding device for positioning said laser beam (80) relative to said median plane, and a welding device for said sheets (11, 12), in the area of removal of the metallic aluminium layer (61, 62),or of aluminium alloy or aluminium-based alloy, so as to obtain a welded joint (63).