How to Choose Suitable Parameters of Metal Fiber Laser Cutter?

For the metal laser cutting machine itself, although it has high precision and high efficiency, a slight change in any parameter during cutting will produce different results. So how can we choose the best suitable machine parameters? Let’s take a look at how to accurately grasp the parameters of the metal laser cutting machine!

In the cutting process of the metal fiber laser cutting machine, the auxiliary air pressure can blow off the slag during cutting and cool the heat-affected zone. Auxiliary gases include oxygen, compressed air, nitrogen, and inert gases.

For some metals like aluminum alloy and nonmetals, inert gas or compressed air is generally used to prevent the material from burning. And for most metal materials, reactive gases like oxygen are used. Because oxygen can oxidize the metal surface and improve the cutting efficiency.

When the auxiliary air pressure is too high, eddy currents appear on the surface of the material, which weakens the ability to remove the melt. Even worse, it will result in a wider slit and a rough cutting surface. But when the air pressure is too low, the melt cannot be completely blown away. And the lower surface of the material will stick to the slag. Therefore, the auxiliary gas pressure should be adjusted during cutting to obtain the best cutting quality.

The metal fiber laser power has a considerable influence on the cutting speed, kerf width, cutting thickness, and cutting quality. And the amount of laser power required is determined by the material and the mechanism. For example, materials with good thermal conductivity, high melting point, and high reflectivity require higher laser power. Generally, there is the most moderate laser power to obtain the best cutting quality in the laser cutting process. If the power is further reduced or increased, slag or over-burning will occur, resulting in a decrease in the processing quality.

In addition, with the increase of the discharge voltage of the metal fiber laser cutting machine, the intensity of the laser will increase due to the increase of the input peak power. So that the diameter of the spot and the width of the slit increase. With the increase of the pulse width, the average power and the width of the laser slit will increase. Usually, with the increase of the pulse frequency, the slit will also become wider. When the frequency exceeds a certain value, the slit width will decrease.

The focus position is the distance from the laser focus to the workpiece surface. It directly affects the roughness of the cut surface, the slope and width of the kerf, and the adhesion of molten residues. If the focus position is too advanced, this will increase the amount of heat absorbed by the lower end of the workpiece. When the cutting speed and auxiliary air pressure are constant, the molten material will adhere to the lower surface of the workpiece in a spherical shape. If the position lags behind, the heat absorbed by the lower end will be reduced. So that the material in the cutting seam cannot be completely melted. And some sharp and short residues will adhere to the lower surface of the plate.

Typically, the focus position should be on the surface of the workpiece or slightly below it. However, different materials have different requirements. When cutting carbon steel, the cutting quality is better when the focus is on the surface of the plate. While cutting stainless steel, the focus should be about 1/2 of the thickness of the plate for better results.

In the metal laser cutting process, the cutting speed has a considerable influence on the quality of the cutting material. The ideal cutting speed will make the cutting surface smooth, and there will be no slag in the lower part of the material. When the auxiliary gas pressure and laser power are constant, the cutting speed is inversely proportional to kerf width.