How to adjust the focal length of fiber laser cutting machine

When the focus of the fiber laser cutting machine is at the best position, the best cutting results can be obtained with the smallest slit and the highest efficiency. Different laser focal positions correspond to different cutting surface roughnesses.The adjustment of the focal position of the fiber laser cutting machine to optimize the cutting quality is determined from the situation where the cutting focus is on the cutting material:

1.Negative focal length

Negative focal length (the cutting focus is on the cutting material) is mainly used when cutting thick metal plates. Negative focal length cutting of thick plates requires a large cutting width, insufficient oxygen leading to the nozzle to reduce the cutting temperature, and the cutting surface is relatively rough, which is not suitable for high-precision precision cutting.

2.Inner negative focal length

The inner negative focal length (the cutting focus is inside the cutting material) is usually applied to fiber laser cutting machines for cutting aluminum, aluminum alloy and stainless steel. The surface is cut according to the principle of focus. The cutting width is larger on the workpiece surface than the cutting point. In this mode, the fiber laser cutting machine has a large air flow, a high temperature, and a long time for cutting the perforation. Therefore, this cutting method is mainly used in cutting hard materials such as aluminum or stainless steel.

3.0 focal length

0 focal length (the cutting focus is on the surface of the cutting material) is usually a focus positioning method suitable for cutting SS41, SPH, SPC and other materials. The focal point of 0-focal cutting is close to the surface of the workpiece. Because the smoothness of the cutting surface is not the same, the upper surface of the cutting is relatively smooth while the lower surface is relatively rough. This cutting focus positioning method needs to be determined according to the actual process requirements of the upper and lower surfaces. According to the actual situation, it is very important to determine the focus position of the fiber laser cutting machine. A reasonable focus position can maximize the use of laser energy, and can make the fiber laser cutting machine work more reasonably.