Direct Diode Laser Multi-Wavelength Sheet Metal Cutting
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Solution Overview
Problem
Existing sheet metal processing methods using laser beams lack a quantitative guarantee of uniform surface roughness, particularly when cutting mild steel and aluminum plates, and do not specify the optimal laser source for achieving this uniformity.
Innovation Solution
A sheet metal processing method utilizing a direct diode laser (DDL) module that oscillates multiple wavelengths, transmitted through a fiber, and processed with a head that condenses the beams onto the metal, using specific parameters such as assist gas pressure, focal length, power density, and nozzle dimensions to achieve surface roughness of ≤0.4 μm for mild steel and ≤2.5 μm for aluminum plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional laser sources (CO2 laser, YAG laser, fiber laser) are used for sheet metal processing, then processing capability is achieved, but surface roughness uniformity cannot be quantitatively guaranteed
Solution Approach 1:
The patent changes the fundamental parameter of laser wavelength from conventional single wavelengths (CO2: 10.6μm, YAG: 1.06μm, fiber: 1.07μm) to multiple wavelengths (400-2000nm range) using a direct diode laser module. This parameter change enables simultaneous optimization of absorption characteristics across different material types and processing depths, achieving quantitative surface roughness control (Ra≤0.4μm for steel, Ra≤2.5μm for aluminum) that was not achievable with conventional single-wavelength sources.
2Manufacturing precision
If multiple laser wavelengths are used to improve surface roughness, then manufacturing precision improves, but device complexity increases
Solution Approach 1:
The patent merges multiple laser diodes emitting at different wavelengths into a single integrated direct diode laser module. This consolidation achieves the benefits of multi-wavelength processing while reducing device complexity compared to using separate laser sources. The module transmits all wavelengths through a single optical fiber, simplifying the overall system architecture while maintaining the ability to achieve Ra≤0.4μm for steel and Ra≤2.5μm for aluminum.
Solution Approach 2:
The direct diode laser module is designed with universal applicability across different sheet metal types (steel, aluminum, stainless steel) and thicknesses (0.5-10mm). The multi-wavelength capability (400-2000nm) allows the same device to optimize absorption for different materials without requiring wavelength-specific configurations, achieving both precision (Ra≤0.4μm) and versatility in a single system.
3Manufacturing precision
If high power density is used to achieve clean cuts, then surface roughness improves, but energy consumption increases
Solution Approach 1:
The patent changes the energy delivery parameter by using multiple wavelengths that can be optimized for different absorption rates. By selecting appropriate wavelength combinations from the 400-2000nm range, the system achieves efficient energy absorption at lower overall power levels while maintaining the high peak power density needed for clean cuts. This results in Ra≤0.4μm surface finish with reduced energy consumption compared to conventional single-wavelength high-power lasers.
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 a quantitatively guaranteed surface roughness for both mild steel and aluminum plates, significantly improving upon existing methods by reducing surface roughness compared to CO2 and fiber laser processing.
Implementation Method 1
a laser processing machine using a direct diode laser (DDL) module as a laser light source has been developed. The DDL module superposes laser beams of multiple wavelengths generated by a plurality of laser diodes (LD)
Implementation Method 2
the laser beams ejected from an end face of the transmission fiber are condensed and irradiated onto a material to be processed (a workpiece) by a collimator lens and a condensing lens
Implementation Method 3
an assist gas is oxygen, and its pressure is 0.05 (MPa) to 0.2 (MPa)... an assist gas is nitrogen, and its pressure is greater than or equal to 0.8 (MPa)
Data Source
AI summary
Using a transmission fiber for transmitting laser beams of multiple wavelengths oscillated by a DDL module, and a laser processing machine for cutting a sheet metal with a processing head that condenses the laser beams of multiple wavelengths and irradiates them onto the sheet metal, a mild steel plate or an aluminum plate is cut, and by cutting a mild steel plate with a thickness greater than or equal to 1 mm and less than or equal to 5 mm, a surface roughness (Ra) of a cut surface of the cut mild steel plate is less than or equal to 0.4 μm, and when an aluminum plate with a thickness greater than or equal to 1 mm and less than or equal to 5 mm is cut, a surface roughness (Ra) of a cut surface of the cut aluminum plate is less than or equal to 2.5 μm.