BLOG

1. The influence of auxiliary air pressure

During laser cutting, auxiliary air pressure can blow off the slag during the cutting process, cooling the cutting heat-affected zone. Auxiliary gases include oxygen, compressed air, nitrogen and inert gases. For some metallic and non-metallic materials, inert gas or compressed air is generally used, which can prevent the material from burning. Such as the cutting of aluminum alloy materials. For most metal materials, reactive gases (such as oxygen) are used, because oxygen oxidizes the metal surface and improves 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, resulting in a widening of the cutting slit and rough cutting surface; 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 rod. Scum scum. Therefore, the auxiliary gas pressure should be adjusted when cutting to get the best cutting quality.

2. The influence of laser power

The size of the laser power has a considerable influence on the cutting speed, cutting width, cutting thickness and cutting quality. The amount of power required depends on the characteristics of the material and the cutting mechanism. For example, materials with good thermal conductivity, high melting point, and high reflectivity of the cutting surface require higher laser power. Generally, under certain other conditions, the laser power for the best cut quality is present in laser cutting machine processing. Further reductions or increases in power can cause slagging or overburning, resulting in a decrease in processing quality.

In addition, with the increase of discharge voltage, the intensity of the laser will increase due to the increase of the input peak power, so that the spot diameter increases, and the slit width also increases accordingly; As the pulse width increases, the average power of the laser increases, and so does the width of the laser slit; In general, as the pulse frequency increases, the slit also widens. When the frequency exceeds a certain value, the slit width decreases.

3. The influence of cutting speed

In laser cutting, the cutting speed has a considerable impact on the quality of the cutting material. The ideal cutting speed will make the cutting surface appear relatively smooth lines, and the lower part of the material will not appear slag. When the auxiliary gas pressure and laser power are constant, the cutting speed is inversely nonlinear to the slit width. When the cutting speed is slower, the laser energy acts in the slit for a longer time, resulting in an increase in the slit width. , When the speed is too slow, the laser beam action time is too long, the difference between the upper seam and the lower seam of the workpiece will be great, the cutting quality will be reduced, and the production efficiency will be greatly reduced. With the improvement of the cutting speed of the fiber laser cutting machine, the action time of the laser beam energy on the workpiece becomes shorter, so that the heat diffusion and heat conduction effect become smaller, and the slit width is correspondingly smaller. When the speed is too fast, the material of the workpiece to be cut will not be cut through due to insufficient cutting heat input. This phenomenon belongs to incomplete cutting, and the melt cannot be blown off in time. These melts will cause the incision to be re-welded.

4. The influence of focus position

Focus position is the distance from the laser focus to the surface of the workpiece, which directly affects the roughness of the cutting surface, the slope and width of the cutting seam, and the adhesion of the slag. If the focus position is too forward, the heat absorbed by the lower end of the cut workpiece will increase. At a constant cutting speed and auxiliary air pressure, the material to be cut and the molten material near the slit will flow on the lower surface in a liquid state. After cooling, the molten material adheres to the lower surface of the workpiece in a spherical shape; If the position lags, the heat absorbed by the lower end face of the material being cut will be reduced, so that the material in the cutting joint cannot be completely melted. Some sharp and short residues will adhere to the surface. In general, the focus position should be on the surface of the workpiece or slightly lower, but different materials have different requirements. When cutting carbon steel, the cutting quality is better when the focus is on the plate surface; When cutting stainless steel, the focus should be on the thickness of the plate.