For most laser cutting processes, the quality evaluation mainly includes the following points:
1. Smooth cutting surface with few lines and no brittle fracture
When the laser cuts the plate at high temperature, no trace of molten material appears in the incision under the vertical laser beam, but in the back of the laser beam.As a result, curved lines are formed at the cutting edge, and these lines closely follow the moving laser beam.To correct this problem, reducing the feed rate at the end of the cutting process can greatly eliminate the line.
2. Narrow slit width (mainly related to the diameter of the laser beam spot and the mass of the laser tube)
Under normal circumstances, cutting width does not affect the quality of cutting.It is only when a particularly precise contour is formed within the part that the cutting width makes a significant difference.This is because the cut width determines the minimum internal longitude of the contour.Therefore, in order to ensure the same accuracy, no matter how wide the cutting is, the workpiece should be kept in the laser cutting machine processing area;
3. Good perpendicularity of joints and small heating area
When the thickness of the processed material exceeds 18mm, the verticality of the cutting edge is very important.When the beam leaves the focus, the beam diverges, and the section of the beam extends either to the top or the bottom, depending on where the focus is.The blade deviates a few millimeters from the vertical line.The more vertical the edge, the higher the cutting quality
4. Effect of cutting material heat
Heat affected area refers to the area heated near the incision during laser cutting.At the same time, the structure of the material itself has changed.For example, some materials will harden.Heat affected zone refers to the regional change of internal structure caused by high temperature.But concave and corrosion have adverse effects on the cutting edge surface, which affects the appearance of laser cutting machine.In general, cutting errors should be avoided.Finally, if cutting causes the part to heat up sharply, the part will deform.This is particularly important for fine machining, where the contours and connectors are usually only a few tenths of a millimeter wide.Controlling laser power and using short laser pulse can reduce element heating and avoid deformation.