How to Eliminate Burrs in Fiber Laser Cutting: A Complete Troubleshooting Guide

Laser cutting is prized for its high precision and smooth edges. However, in actual production, burrs (slag) remain a common challenge that can compromise product quality and drive up post-processing costs. Understanding the technical root causes is the first step toward achieving a perfect, burr-free cut.

Burrs are essentially molten metal that hasn't been fully evacuated by the assist gas, causing it to resolidify on the bottom edge of the workpiece.

• Focus Position Deviation:

  • Focus too high: The laser energy disperses, and the bottom of the kerf doesn't melt sufficiently.

  • Focus too low: The energy is too concentrated at the bottom, creating excessive melt that the gas cannot blow away effectively.

• Assist Gas Issues:

  • Insufficient Pressure: The gas lacks the kinetic energy to push the molten material out.

  • Wrong Gas Type: Using Oxygen for stainless steel increases melt viscosity due to the resulting oxide layer.

• Improper Cutting Speed:

  • Too Slow: Excessive heat buildup causes the molten pool to expand.

  • Too Fast: The material is not fully penetrated, leading to "melt drag" and sharp burrs.

• Nozzle Condition:

  • A worn or misaligned nozzle causes eccentric airflow, leading to uneven slag removal.

• Mild Steel: Medium tendency. Oxygen is standard for thick plates, while Nitrogen provides a cleaner edge for thin sheets.

• Stainless Steel: High tendency. High-pressure Nitrogen is mandatory to prevent oxidation and ensure a bright finish.

• Aluminum & Brass: Very high tendency due to high reflectivity and thermal conductivity. Requires maximum gas pressure and precise focus settings.

1. Daily Beam Alignment: Check the beam-to-nozzle centering every morning before starting production.

2. Gas Purity: Always use assist gases with a purity of ≥99.9%.

3. Parameter Optimization: Record a "Golden Table" of parameters for different materials and thicknesses to avoid trial-and-error waste.