Standard for judging the processing quality of laser cutting machine?

In the laser cutting process of general materials, due to the faster cutting speed, the thermal deformation of the parts is very small,  the dimensional accuracy of the cut parts mainly depends on the mechanical accuracy control accuracy of the worktable of the laser cutting machine. In the pulse laser cutting process , high-precision cutting equipment  control technology are used,  the scale accuracy can reach um level.

For laser cutting, the evaluation of its processing quality mainly includes the following principles:

1. The cutting is smooth, without streaks  without brittle fracture;

2. The slit width is narrow, which is mainly related to the diameter of the laser beam spot;

3. The verticality of the slit is good,  the heat affected zone is small;

4. No material is burned, no molten layer is formed, no large slag;

5. The surface roughness of the cut, the size of the surface roughness is the key to measuring the quality of the laser cutting surface.

In addition to the above principles, the state  final shape of the melted layer during processing directly affect the above processing quality evaluation indicators.

  Laser cutting surface roughness mainly depends on the following three aspects:

 1. The inherent parameters of the cutting system, such as the spot pattern, focal length, etc.;

 2. Adjustable process parameters during cutting, such as power, cutting speed, auxiliary gas type  pressure, etc.;

 3. Physical parameters of the processed materials, such as laser absorption rate, melting point, viscosity coefficient of molten metal oxide, surface tension of metal oxide, etc. In addition, the thickness of the workpiece also has a great influence on the quality of the laser-cut surface. Relatively speaking, the smaller the thickness of the metal workpiece, the higher the roughness grade of the cut surface.

In order to obtain a better surface quality level, the laser power, cutting speed  other process parameters must be optimized many times. Generally speaking, for materials with the same characteristics  thickness, a set of cutting process parameters will also result in different surface quality of the cut. The melting point of metal materials is low, the thermal conductivity is large, the viscosity coefficient of the melt is small,  the surface tension of metal oxides is small. It is easy to obtain a high surface quality during laser cutting. When laser cutting a flat plate, it is easy to measure the surface quality, but when performing fine processing  cutting some complex patterns, it is difficult to directly measure it,  only by optimizing the test parameters to control its surface quality. 

Therefore, in order to facilitate automated cutting, the correspondence between externally optimized parameters  surface quality levels should be established.