Cutting Principle of Laser Cutting Machine

Laser cutting machine focuses the laser beam of high power density through the optical system, which is emitted from the laser. The laser beam irradiates the surface of the workpiece, so that the workpiece reaches the melting point or boiling point. At the same time, the high-pressure gas coaxial with the beam will blow away the melted or gasified metal.

With the relative position of the beam and the workpiece moving, the material will eventually form a slit to achieve the purpose of cutting.

Laser cutting is an invisible beam instead of the traditional mechanical knife. It has the characteristics of high precision, fast cutting, not limited to cutting patterns, automatic layout, material saving, smooth cutting and low processing cost. It will gradually improve or replace the traditional metal cutting process equipment. The mechanical part of the laser tool head has no contact with the workpiece and will not scratch the surface of the workpiece in the work; the laser cutting speed is fast, the incision is smooth and flat, and generally does not need follow-up processing; the cutting heat affected zone is small, the deformation of the plate is small, the slit is narrow (0.1mm~0.3mm); the incision has no mechanical stress and no shear burr; the processing accuracy is high, the repeatability is good, and the material surface is not damaged; Programming, can process arbitrary plane drawing, can cut the whole board with large breadth, no need to open the die, economical and time-saving.

Laser is a kind of light, which, like other natural light, is produced by atom (molecule or ion, etc.) transition. However, unlike ordinary light, laser depends on spontaneous emission only in the initial very short time, and the subsequent process is completely determined by stimulated radiation. Therefore, laser has very pure color, almost no divergence direction, extremely high luminous intensity and high coherence.

Laser cutting is realized by using high power density energy produced by laser focusing. Under the control of computer, the laser is discharged by pulse, and the controlled repetitive high frequency pulsed laser is output to form a beam with a certain frequency and pulse width. The pulsed laser beam is transmitted and reflected through the optical path and focused on the surface of the processed object through the focusing lens group, forming a fine, high energy density spot near the surface to be processed. The material is processed by instantaneous melting or gasification at high temperature. Every high-energy laser pulse instantaneously splashes a small hole on the surface of the object. Under the control of computer, the laser processing head and the processed material move continuously and relative to each other according to the pre-drawn figure, so that the object can be processed into the desired shape.

The process parameters (cutting speed, laser power, gas pressure, etc.) and trajectory of slit cutting are controlled by numerical control system. The slag at the slit is blown away by auxiliary gas under certain pressure.