Laser Cutting of Highly Reflective Materials？
5 Key Considerations for Sheet Metal Professionals
In sheet metal processing, highly reflective materials such as aluminum, copper, and brass are widely used due to their advantages of light weight and good electrical conductivity. However, the “reflection challenge” during laser cutting often troubles many enterprises — reflected light can damage the laser head, reduce cutting accuracy, and even cause equipment failures. Today, we’ll share 5 concise practical tips to help you tackle the cutting of highly reflective materials and minimize production risks.
1. Choose the Right Equipment: Avoid Reflection Damage from the Source
- Prioritize “high-reflection dedicated laser heads”: Ordinary laser heads have weak anti-reflection capabilities. It is recommended to replace them with dedicated heads featuring “anti-reflection coatings” or “dual optical path design,” which can effectively absorb reflected light and reduce the risk of lens cracking;
- Select the appropriate laser type: Fiber lasers (especially those with a wavelength of 1064nm) have better absorption rates for highly reflective materials compared to CO₂ lasers. For cutting medium and small thicknesses (aluminum ≤ 8mm, copper ≤ 5mm), fiber laser equipment is the preferred choice;
- Check equipment protection functions: Ensure the laser machine is equipped with “reflected light detection” and “overcurrent protection” functions. Once strong reflected light is detected, it can automatically reduce power or pause cutting to avoid damaging the laser generator.
2. Optimize Process Parameters: Don’t Ruin Workpieces with “Wrong Parameters”
- Power: “Better Low Than High”; Speed: “Better Slow Than Fast”: Highly reflective materials are prone to over-melting due to concentrated energy. It is recommended to reduce the power by 10%-20% compared to cutting carbon steel and appropriately lower the speed (e.g., the cutting speed for aluminum sheets can be set to 60%-80% of that for carbon steel);
- Focus position: “Shift Upward”: The focus for conventional cutting is on the material surface. For highly reflective materials, it is advisable to shift the focus upward by 0.5-1mm to reduce direct reflection of the laser beam back to the laser head while improving the flatness of the cut edge;
- Choose the right auxiliary gas and pressure: Use nitrogen for aluminum cutting (to avoid oxidation) with a pressure controlled between 0.8-1.2MPa; use oxygen for copper cutting (to enhance heat absorption) with a pressure of 0.5-0.8MPa. The gas purity must be ≥ 99.99% to prevent impurities from affecting the cut quality.
3. Material Preprocessing: Small Details Avoid Big Troubles
- Clean surface oil stains/oxide layers: Oil stains and oxide films on the surface of highly reflective materials will reduce laser absorption. Before cutting, clean the surface with alcohol or acid pickling to ensure it is free of contaminants;
- Secure the workpiece properly: Use dedicated fixtures to press the material firmly to prevent beam deviation caused by workpiece shaking during cutting. At the same time, reserve a “reflection avoidance space” to prevent reflected light from directly hitting equipment components.
4. Operation Specifications: Safety Always Comes First
- Mandatory “inspection” before startup: Before each cutting operation, check if the laser head lens has scratches or looseness, and ensure the water and gas circuits are unobstructed. Only start the equipment after confirming no abnormalities;
- “Never leave unattended” during cutting: Assign a dedicated operator to monitor the cutting process of highly reflective materials. Observe the cut edge status and equipment temperature in real time. Immediately stop the machine for inspection if “abnormal sparks” or “alarm prompts” occur;
- Take personal protection measures: Wear dedicated laser safety goggles to avoid direct exposure of eyes to strong light. Set up warning signs in the operation area and prohibit non-operating personnel from approaching.
5. After-Sales Maintenance: The Key to Extending Equipment Lifespan
- Clean promptly after cutting: After each processing session, use compressed air to clean dust from the laser head lens and guide rails. Regularly (weekly is recommended) wipe the lens with a dedicated cleaning agent to maintain light transmittance;
- Calibrate equipment parameters regularly: Calibrate the laser focus and power parameters quarterly based on the thickness and type of the material being cut to ensure stable cutting accuracy;
- Choose a professional after-sales team: If the equipment experiences “faults caused by reflection” (such as laser generator damage or lens cracking), do not disassemble it yourself. Contact professional technicians from the equipment manufacturer for repairs to avoid secondary damage.
Conclusion: The core of laser cutting highly reflective materials lies in “selecting the right equipment + optimizing processes + following standard operations.” By implementing these 5 key points, you can not only improve cutting efficiency and workpiece quality but also reduce the risk of equipment failures, helping sheet metal enterprises save costs. Have you encountered any problems when cutting highly reflective materials? Feel free to leave a comment below to discuss!
more photos：https://fuleimetal.com/project-case/
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