Oscillating Laser Welding With Filler Wire for Large-Gap Aluminum Joints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional welding methods for aluminum alloy materials, such as laser welding, often result in porosity defects and the formation of brittle phases due to interfacial reactions between reinforcement phases and the aluminum matrix, especially in composite materials like SiCp/Al, which affects the strength of the joint and is challenging to apply efficiently in complex aerospace structures.
Innovation Solution
An oscillating laser welding method with filler wires that reserves a gap between aluminum alloy sheets to reduce dilution and prevent porosity and brittle phase formation, using a wire feeding nozzle and laser welding head to fill the gap with molten wires, while maintaining a stable molten pool and controlling the oscillating path to enhance energy utilization and reduce residual stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional laser welding is used to join aluminum alloy sheets, then welding efficiency is improved, but porosity defects and brittle phase formation occur due to high dilution rate
Solution Approach 1:
The patent applies preliminary action by pre-reserving a gap between the aluminum alloy sheets before welding. This gap is intentionally designed and maintained throughout the welding process to control the molten pool formation and reduce dilution. The gap serves as a pre-established structural feature that prevents direct contact between the base metals, thereby avoiding porosity and brittle phase formation while maintaining high welding efficiency through oscillating laser and filler wire technology.
2Strength
If solid-phase welding is used to avoid brittle phase formation, then joint strength is improved, but welding efficiency decreases and application flexibility is limited
Solution Approach 1:
The patent applies parameter changes by transforming the welding process from traditional fusion welding to oscillating laser welding with a reserved gap. This changes the thermal field distribution, molten pool dynamics, and material mixing characteristics. The oscillating laser creates a dynamic molten pool that reduces dilution while maintaining adequate fusion, and the reserved gap parameter controls the interaction between filler wires and base metals, achieving both high joint strength and welding efficiency.
3Strength
If the gap between sheets is reduced to improve joint fusion, then welding strength is improved, but porosity and brittle phases increase due to higher dilution
Solution Approach 1:
The patent applies dynamics by introducing oscillating motion to the laser beam during welding. The oscillating laser creates a dynamic molten pool that enhances material mixing and heat distribution while controlling dilution. Combined with the static reserved gap, this dynamic approach allows the molten pool to penetrate and fill the gap effectively, achieving strong joints without the porosity and brittle phases associated with static gap welding.
4Device complexity
If traditional laser welding is used without filler wires, then process simplicity is maintained, but gap filling capability and joint quality deteriorate
Solution Approach 1:
The patent applies the intermediary principle by introducing filler wires as a mediating material between the two aluminum alloy sheets. The filler wires, fed through the reserved gap, serve as an intermediate substance that facilitates proper gap filling and joint formation. This intermediary approach enables precise control over the weld metal composition and distribution, achieving high manufacturing precision without excessively complicating the overall welding process.
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 reduces porosity and brittle phase generation, improves the strength of the weld, and allows for faster welding with reduced residual stress, overcoming limitations of traditional laser welding such as narrow gap constraints and poor welding efficiency, resulting in high-quality joints with improved tensile strength and ductility.
Implementation Method 1
forming a molten pool on the guiding plate through the laser beam and the aluminum alloy welding wires, and moving and guiding the molten pool into the gap, such that the aluminum alloy welding wires are heated and molten by the laser beam to fill all of the gap
Implementation Method 2
Oscillating laser welding with filler wires for jointing aluminum alloy sheets with a large gap therebetween
Data Source
AI summary
An oscillating laser welding with filler wires for jointing aluminum alloy sheets with a large gap therebetween, including the following steps: providing two aluminum alloy sheets first, and reserving a gap (2) and keeping the gap with a constant width between opposite surfaces of the two aluminum alloy sheets to be jointed; providing a laser welding head (1), a wire feeding nozzle (3), and a protective gas nozzle (4) above the gap; presetting a welding start guiding plate (5) at a welding starting end of the gap, forming a molten pool on the welding start guiding plate by a laser beam, and guiding the molten pool to the welding starting end of the gap; and enabling the wire feeding nozzle and the laser welding head to correspond to the gap and travel in the same direction. The aluminum alloy welding wires fill the whole gap after being heated and molten by the laser beam, and the welding of the two aluminum alloy sheets is completed. The melting amount of the aluminum alloy sheets by the laser beam can be reduced as much as possible, so that a dilution rate of a welding joint and generation of a metallurgical reaction brittle phase can be reduced, and the porosity of the joint can further be reduced. Welding of conventional aluminum alloys, aluminum matrix composite materials, and additive-manufactured aluminum alloy sheets can be realized.