Composite Laser Beam Welding for Stable Aluminum Weld Seams
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laser welding of metals, particularly with one-micrometer waveband lasers, faces issues such as widened melt widths, self-burning, and irregular weld seams due to variations in penetration, which impair the quality of the weld and kerf control.
Innovation Solution
A composite laser beam configuration comprising a circular center beam and an annular ring beam with a wavelength difference of at least 10 nanometers or a spectrum width of 10 nanometers, generated by a fiber laser or fiber-coupled laser device, is used to improve welding quality by reducing penetration variations and minimizing porosity and spatter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a one-micrometer waveband laser beam with Gaussian beam profile is used, then high optical energy intensity and absorbance are achieved, but melt width widens and kerf control deteriorates
Solution Approach 1:
The laser beam is segmented into multiple beams arranged in a matrix pattern (e.g., 3x3, 4x4, or 5x5 arrangement). Each individual beam maintains high energy density, while the distributed pattern prevents excessive melt width accumulation, thereby preserving kerf control alongside high energy intensity.
Solution Approach 2:
The beam profile transitions from a symmetric Gaussian distribution to an asymmetric matrix arrangement of discrete beams. This asymmetric configuration allows optimized energy distribution across the workpiece surface, maintaining peak intensity at each beam location while controlling overall melt pool geometry for precise kerf width.
2Productivity
If a one-micrometer waveband laser beam is used with oxygen assist gas, then cutting capability is improved, but self-burning occurs and weld quality deteriorates
Solution Approach 1:
The concentrated single beam is segmented into multiple lower-power beams arranged in a matrix. This distribution reduces the risk of self-burning by avoiding excessive energy concentration in any single location, while the collective energy of all beams maintains effective cutting capability. The segmented pattern allows better control of the molten metal flow and oxidation process.
3Device complexity
If conventional single beam profile is used, then processing is simple, but penetration varies along weld seam causing irregular weld quality
Solution Approach 1:
The single beam is segmented into multiple beams arranged in a matrix pattern. This segmentation enables more uniform energy distribution across the weld seam, ensuring consistent penetration depth along the entire weld path. The multiple beams work in parallel to maintain uniform heating and melting, producing regular and high-quality weld seams.
Solution Approach 2:
Multiple individual laser beams are merged into a single composite beam pattern that acts as one unified processing source. The combined effect of all matrix-arranged beams provides uniform penetration along the weld seam, achieving consistent weld quality while the beams are delivered through a single optical fiber bundle.
4Manufacturing precision
If higher power levels are used to maintain welding quality, then weld quality is improved, but processing speed decreases and energy consumption increases
Solution Approach 1:
The total required power is segmented across multiple beams in the matrix arrangement. Each beam operates at an optimized power level that maintains high weld quality through consistent penetration, while the parallel operation of multiple beams enables faster processing speeds. This segmentation allows the system to achieve both high quality and high productivity simultaneously.
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 configuration achieves improved weld seam quality, reduced porosity, and increased stability of the melt pool, allowing for lower power levels and faster welding speeds while maintaining high-quality welds, especially in aluminum alloys.
Implementation Method 1
at least one first laser device, each providing at least one first optical feed fiber with a first laser beam
Implementation Method 2
at least one second laser device, each providing at least one second optical feed fiber with a second laser beam
Implementation Method 3
the laser beam is typically condensed through a condenser lens into a spot of 100-500 μm to increase energy density and instantaneously heat the workpiece to a temperature of 1500° C. or over so that the workpiece melts
Implementation Method 4
means for generating a composite laser beam comprising a first output laser beam and a second output laser beam
Data Source
AI summary
The invention concerns an apparatus and its use for laser welding. A laser welding apparatus comprise at least one first laser device, each providing at least one first optical feed fiber with a first laser beam; at least one second laser device, each providing at least one second optical feed fiber with a second laser beam; means for generating a composite laser beam comprising a first output laser beam and a second output laser beam for welding a workpiece; wherein the first output laser beam has a circular cross-section and the second output laser beam has an annular shape concentric to the first output laser beam. The second laser device is a fiber laser device or a fiber-coupled laser device. The apparatus is configured to form the second output laser beam at least on the basis of the second laser beam, and the second output laser beam comprises a first wavelength and a second wavelength having difference of at least 10 nanometers, or the second output laser beam has spectrum width of least 10 nanometers.