Fiber laser cutting machines are the modern mainstream choice for cutting aluminum sheets, offering excellent results. Traditional CO2 laser cutting machines, however, face significant difficulties and limitations when cutting aluminum sheets.
1. Comparison of the performance of different types of laser cutting machines
1. Fiber laser cutting machine： Aluminum cutting performance: Excellent
Advantages
1. Excellent beam quality: Short wavelength, aluminum has a higher absorption rate, resulting in high efficiency.
2. Fast cutting speed: Far superior to CO2 laser cutting machines.
3. Excellent cut quality: Narrow kerf, smooth cross-section, and high precision.
4. Low energy consumption: High electro-optical conversion efficiency and low operating costs.
Disadvantages and considerations
1. Limitations on thick plates: Although superior to CO2 cutting machines, it still has difficulty cutting extremely thick aluminum sheets (e.g., >25mm), resulting in reduced cross-section quality.
2. Requires high-pressure gas: High-purity nitrogen (N₂) is typically used as an assist gas to prevent oxidation and achieve a bright cross-section.
2. CO2 Laser Cutting Machine ：Aluminum Cutting Results: Average/Poor
Advantages
1. Mature technology for cutting non-metals and thin steels. |
Disadvantages and Considerations
1. Low absorptivity: Aluminum is a highly reflective material, easily reflected by the CO2 laser wavelength, resulting in low efficiency and extremely damaging the laser head.
2. Requires special processing: The aluminum surface must be coated with an anti-reflective coating (such as phosphoric acid or graphite), increasing the process and cost.
3. Slow speed and high energy consumption.
4. High risk: Reflected laser energy can damage the machine itself. |
Conclusion: If your primary goal is to cut aluminum, definitely choose a fiber laser cutting machine.
2. Specific Cutting Performance (Specific to Fiber Laser)
Cutting Thickness:
Thin to medium-thick plates (≤10mm): Excellent results. It offers fast speeds, smooth, burr-free cross-sections, and very high precision, making it the preferred processing method.
Thick plates (10mm - 20mm): Excellent results. Requires a higher-power laser (e.g., 3000W and above) and optimized process parameters. Slight dross may form on the cross-section, but it is easy to clean.
Extremely thick plates (>20mm): Average results. Requires a very high-power laser (e.g., 6000W and above), resulting in slower cutting speeds, lower cross-section quality, and more dross. Water jet or plasma cutting may be considered as alternatives.
Cut Quality:
Cutting with nitrogen (N₂): The cross-section is a silvery-white metallic color, very bright, and free of oxide layers, making it suitable for direct welding and easy subsequent processing.
Cutting with oxygen (O₂): The cross-section forms a black aluminum oxide film, resulting in a rough and poor-quality surface. It is generally only used for rough machining where appearance is not a priority.
Precision and Speed:
Extremely High Precision: Thanks to non-contact machining and a CNC system, it can achieve fine cutting of even the most complex patterns, with repeatability accuracy reaching ±0.05mm.
Extremely Fast Speed: Far exceeding traditional methods like wire cutting and water jet cutting, resulting in high production efficiency.
3. Key Considerations for Cutting Aluminum Sheets
1. Laser Power: The higher the power, the thicker the aluminum sheet can be cut. Recommended Power:
Under 6mm: 1000W - 1500W
8mm - 12mm: 2000W - 3000W
15mm - 20mm: 4000W - 6000W
Over 20mm: ≥6000W
2. Assist Gas: High-purity (≥99.99%) nitrogen must be used, and the pressure must be sufficiently high (typically >1.2MPa) to ensure the removal of molten metal and an oxidation-free cut surface. This is a key process for ensuring optimal cutting results.
3. Plate Surface Treatment: Anodized layers, oil stains, or coatings on aluminum plates can affect cutting quality and consistency, so they should be cleaned before cutting.
4. Reflection Risk Prevention: Although fiber lasers have a higher absorption rate for aluminum, the risk of reflection still exists. High-quality laser heads are equipped with an anti-reflection device (ARD) that automatically protects against abnormal reflections, preventing core components from burning.
5. Dust Management: Aluminum metal dust is not only harmful to health but also poses an explosion risk when reaching certain concentrations in the air. Therefore, laser cutting machines must be equipped with a high-performance dust removal system to promptly remove dust.
Summary
Laser cutting machines (specifically fiber lasers) generally offer excellent results for cutting aluminum plates, especially for plates under 16 mm. They offer absolute advantages in precision, speed, and efficiency, making them a mainstream choice in modern metal processing.
Final advice: Before purchasing equipment, it is best to provide your material sample (material and thickness) to the equipment supplier for a test cut. This is the most intuitive and reliable way to verify cutting results.