A comprehensive comparison of laser cutting different metals. Learn how material properties affect cutting parameters, edge quality, and processing considerations.
Introduction
One of the strengths of fiber laser cutting is its ability to process a wide range of metals. Each material behaves differently due to unique physical and optical properties. At Fulei Metal, we cut all common metals and many specialty alloys.
Material Properties That Affect Laser Cutting
Absorptivity
Carbon steel has high absorptivity at 35-40 percent. Stainless steel at 30-35 percent. Aluminum at 5-8 percent. Copper at 2-5 percent. Brass at 3-6 percent.
Thermal Conductivity
Carbon steel at 50 W/mK is moderate. Stainless at 16 W/mK is low. Aluminum at 237 W/mK is very high. Copper at 401 W/mK is extremely high. Brass at 120 W/mK is high.
Reflectivity
Carbon steel and stainless have low reflectivity. Aluminum, copper, and brass have high reflectivity requiring back-reflection protection.
Carbon Steel (Mild Steel)
The easiest and most commonly laser-cut metal. With oxygen, the exothermic reaction enables fast cutting up to 20-25 mm. Oxygen cutting produces slight oxide. Nitrogen cutting produces clean bright edges.
Stainless Steel
Cuts well with nitrogen to preserve corrosion resistance. Speeds range from 6,000 mm/min for 1 mm to 600 mm/min for 10 mm. Nitrogen produces excellent bright, smooth, oxide-free edges. HAZ is small at 0.05-0.15 mm.
Aluminum
Challenging due to high reflectivity and conductivity but manageable with fiber lasers. Nitrogen only (oxygen is dangerous). Speeds from 5,000 mm/min for 1 mm to 500 mm/min for 10 mm. High gas pressure of 14-25 bar essential. Soft surface requires careful handling.
Copper
One of the most challenging metals. Only fiber lasers with back-reflection protection can cut it. Speeds from 3,000 mm/min for 1 mm to 800 mm/min for 3 mm. Maximum thickness 3-5 mm. Higher power improves performance.
Brass
Slightly easier than copper. Nitrogen at 16-22 bar. Speeds from 3,500 mm/min for 1 mm to 1,000 mm/min for 3 mm. Maximum thickness 4-6 mm.
Specialty Materials
Titanium cuts well with nitrogen or argon, never oxygen. Nickel alloys are challenging. Galvanized steel cuts like carbon steel but zinc coating causes dross and fumes.
Conclusion
Different metals respond differently to laser cutting. Understanding these differences is essential for optimal results. At Fulei Metal, our experience cutting all common metals enables us to select the right parameters for each material.