High power laser metal cutting machine is a advanced manufacturing technology . Because laser metal cutting technology combines laser optics, electronics, machinery and so on. The process of laser cutting is complicated. And there are many influencing factors.
Metal laser cutting work includes laser output power, cut speed and material properties, etc. If the parameters are wrong, the cutting quality will be greatly worse, such as rough cutting surface, notch on the cutting surface or slagging on the back.
Cutting speed of laser metal cutting machine
Too fast or slow speed will affect the quality of cutting, resulting in slagging or cut through.
When the cutting speed is too slow, the laser energy density is too large. And the heat affected zone becomes larger. This will lead to the increase of slagging, wide cut joint and rough cut. When the cutting speed is too high, the laser energy density is small and it may not be cut through.
Notch perpendicularity and slagging height are most sensitive to velocity parameters, followed by notch width and surface roughness.
Operations that increase cutting speed include:
- Increase of laser power.
- Change beam mode.
- To reduce the size of a focus spot (for example by using a short focal length lens).
Focus position of laser metal cutting machine
The size of the spot is proportional to the focus length after the laser beam concentrating. The light spot size is very small and the power density at the focal point is very high after the beam focus with a short focus length, which is favorable to material cutting. But its disadvantage is that the focus length is very short, the adjustment margin is very small, and it is generally suitable for fast laser metal cutting thin materials. For the laser metal cutting machinde with thick material, because the long focus length has wide focal depth, so long as it has enough power density, it is suitable to cut it. Because of the highest power density at the focal point, in most cases, the focus position is just on metal material surface, or slightly below the metal material surface, at the time of cutting. Ensuring that the relative position of the focus. And the metal sheet is constant is an important condition for achieving stable cutting quality. Sometimes the focus length changes due to poor cooling in the work of the lens, which requires the timely adjustment of the focal position.
Post time: Dec-29-2018