Does the laser nozzle affect the quality of laser cutting? Absolutely! Many factors influence laser cutting quality, and the laser nozzle is certainly one of them. The quality, condition, and parameter settings of the laser nozzle directly impact the final result.
The Laser Nozzle’s Influence on Cutting Quality
Firstly, the coaxiality of the laser nozzle center and the laser beam center is critical. If they are misaligned, several problems can occur:
- Degraded Cut Edge Quality: Uneven gas flow from the laser nozzle leads to inconsistent cut edges, with dross on one side and not the other. This is more pronounced in thicker materials, even preventing cutting altogether.
- Sharp Corner Issues: Localized over-melting occurs when cutting sharp corners or small angles. For thicker materials, cutting might become impossible. Therefore, you need to adjust the laser nozzle.
- Unstable Piercing: The piercing process becomes inconsistent, and timing is difficult to control. Thick materials may experience over-melting, while thin materials are less affected. So, the laser nozzle impacts piercing.
Selecting the Right Laser Nozzle Orifice Diameter
Common laser nozzle orifice diameters include φ1.0mm, φ1.5mm, φ2.0mm, φ2.5mm, and φ3.0mm. Currently, φ1.5mm and φ2mm are the most frequently used. Different thicknesses require different laser nozzle sizes:
- Thin Sheets (Under 3mm):
— φ1.5mm laser nozzle: Provides a finer cut surface.
— φ2mm laser nozzle: Results in a rougher cut surface, potentially with dross in corners. - Thick Plates (Over 3mm):
— φ1.5mm laser nozzle: Due to the smaller gas diffusion area, cutting stability is slightly reduced, but it’s generally usable.
— φ2mm laser nozzle: The larger gas diffusion area and slower gas flow result in more stable cutting. Thus, the laser nozzle size matters for gas flow. - φ2.5mm Diameter: Typically used for cutting thick plates over 10mm.
In summary, the laser nozzle orifice size significantly impacts cutting and piercing quality. In practice, φ1.5mm and φ2mm laser nozzles are the most widely used.
However, selecting a larger laser nozzle orifice diameter can negatively affect the protection of the focusing lens. Molten material sparks generated during cutting are more likely to fly upwards, increasing the risk of damage and shortening the lens’s lifespan. Hence, consider lens protection when choosing a laser nozzle.
Laser Nozzle Maintenance and Precautions
The concentricity of the laser nozzle center and the laser beam is a key factor in determining cutting quality, especially when cutting thicker workpieces. Therefore, regularly adjust the laser nozzle center to align with the laser for better cutting results.
Also, handle laser nozzles carefully to prevent deformation from impacts. Deformed or slag-covered laser nozzles severely affect cutting quality and should be cleaned or replaced promptly. High-quality laser nozzles require high manufacturing precision and proper installation. If frequent adjustments are needed due to poor laser nozzle quality, replace the laser nozzle immediately.