Sheet Metal Laser Cutting Technique

1. Types of Laser Cutting

a. CO₂ Laser

Best for: Non-metals (acrylic, wood) and thin metals (<6mm).

Wavelength: 10.6 μm (infrared).

Pros: Cost-effective, good for organic materials.

b. Fiber Laser

Best for: Metals (steel, aluminum, copper, brass).

Wavelength: 1.06 μm (near-infrared).

Pros: Faster, more energy-efficient, better for reflective metals.

c. Nd:YAG Laser

Best for: High-precision cutting (e.g., medical devices).

Wavelength: 1.064 μm.

Pros: Pulsed cutting for delicate work.

        2. Key Laser Cutting Parameters

Parameter	Effect	Typical Setting (Mild Steel)
Laser Power	Higher = Faster cutting, but risk of burrs	1–6 kW (depends on thickness)
Cutting Speed	Too fast = Incomplete cuts; too slow = Overburn	1–10 m/min (adjust per material)
Assist Gas	Removes molten metal, prevents oxidation	O₂ (carbon steel), N₂ (stainless, aluminum)
Nozzle Diameter	Affects beam focus & gas pressure	1–3 mm
Focal Length	Determines kerf width & precision	Adjust based on material thickness

3. Material-Specific Tips

a. Carbon Steel

Best Gas: Oxygen (O₂) → Exothermic reaction boosts cutting speed.

Edge Quality: Slight oxidation (can be cleaned with grinding).

b. Stainless Steel

Best Gas: Nitrogen (N₂) → Prevents oxidation, keeps edges clean.

Challenge: Reflective surface may require higher power.

c. Aluminum

Best Gas: Nitrogen (N₂) or Argon (for high reflectivity).

Issue: High thermal conductivity → Requires higher power.

d. Copper & Brass

Challenge: Highly reflective → Fiber laser preferred.

Tip: Use anti-reflective coatings if needed.

4. Design Considerations for Laser Cutting

✔ Kerf Width Compensation

Laser removes material (~0.1–0.3mm kerf).

Adjust CAD dimensions to account for material loss.

✔ Minimum Hole & Slot Size

Hole Diameter ≥ Material Thickness (e.g., 1mm hole in 1mm sheet).

Slot Width ≥ 0.5× Thickness.

✔ Avoid Sharp Internal Corners

Use small radii (≥0.5mm) to prevent stress concentrations.

✔ Nesting for Efficiency

Arrange parts closely to minimize material waste.

5. Common Defects & Solutions

Defect	Cause	Fix
Burrs	Low power, wrong gas, or slow speed	Increase power, use N₂ for clean cuts
Overburn	Too slow or high power	Optimize speed & power
Dross (Sticky Residue)	Incorrect gas pressure	Increase assist gas pressure
Warping	Excessive heat input	Use pulse cutting or lower power

6. Post-Processing Options

Deburring: Tumbling, grinding, or sanding.

Powder Coating/Painting: Laser-cut edges must be clean and oxide-free.

Bending: Ensure cut edges are smooth to prevent cracking.

7. Advantages of Laser Cutting

✅ High precision (tolerances ±0.1mm).

✅ No tool wear (unlike mechanical cutting).

✅ Complex shapes possible (intricate designs).

✅ Fast setup (digital files, no dies).

Final Recommendation

For sheet metal, fiber lasers are the best choice due to speed and precision. Always test-cut a small sample to optimize parameters before full production.

Would you like help with laser-cutting cost estimation or design file preparation (DXF optimization)? contact Xucheng team to help you!