One article to understand the four evaluation criteria of laser cutting quality

The application of laser cutting in metal materials has been widely known, but many people do not know how to judge the quality of processing when using laser cutting machines. In fact, the cutting quality is usually judged from the perspectives of end surface roughness, bottom burr, verticality, and kerf width.

1. End surface roughness

When the laser is cutting materials, affected by the airflow and feed speed, the end face will form vertical (or inclined) lines. The deeper the line, the rougher the end face, and the shallower the line, the smoother the end face. Roughness affects not only edge appearance, but also friction characteristics, so lower roughness means better cut quality. By adjusting parameters such as laser power, feed speed, focal length, auxiliary gas type and air pressure, the end face roughness can be continuously optimized.

2, the bottom burr

The principle of laser cutting metal is to instantly vaporize the material through the high energy of the laser, and blow away the slag on the surface of the workpiece through the auxiliary gas. However, in the actual processing process, factors such as thick plate, insufficient air pressure, and mismatching feed speed will cause part of the molten slag to form burrs after cooling and hang on the bottom of the workpiece. At this time, additional deburring work is required, which consumes extra man-hours. The burr and slag at the bottom of the workpiece are very important criteria for judging the cutting quality.

3. Verticality

For thin sheet materials, the squareness of laser cutting is negligible, but when the material thickness exceeds 10mm, the squareness of the cutting edge is very important. As you move away from the focal point, the laser beam becomes divergent and the cut widens towards the top or bottom depending on the position of the focal point. The cutting edge deviates from the vertical line by a few percent of a millimeter, the more vertical the edge, the higher the cutting quality.

4, the slit width

The kerf width is the embodiment of the machining accuracy, which usually does not affect the cutting quality. The kerf width becomes an important indicator only when a particularly precise contour and pattern need to be formed inside the workpiece. The width of the kerf determines the minimum inner diameter of the contour. The smaller the kerf width, the more precise the contour and the smaller the hole diameter can be processed. This is one of the important advantages of laser cutting instead of plasma cutting. However, as the thickness of the sheet increases, the kerf width inevitably increases. To ensure stable high-precision cutting, it is necessary to ensure that the workpiece is stable in the processing area of the laser cutting machine.