The process of generation of laser beams for laser cutting involves stimulation of a lasing material inside an enclosed container using electrical discharges. When the lasing material becomes stimulated, partial mirrors inside the container reflect the beams until adequate energy is achieved to escape as a cascade of homochromous coherent light. Fiber optics is used to guide the coherent light to a lens which then concentrates the laser light to the material to be cut. The diameter of the narrowest part of the laser beam is less than 0.01250 inches. Before cutting is begun at a place other than the edge of the material, the material is pierced using a high-power pulsed beam.
The beam is lens-intensified to about 0.001 inches so as to ensure that the beam is of high intensity and rotated during cutting process so as to ensure a smooth surface.
TECHNIQUES FOR LASER CUTTING
Melt and blow: This is also called fusion cutting, melt and blow cutting utilizes high pressure gases to blow away the molten material from the work area. This has the effect of decreasing by a large extent the amount of energy required.
Reactive cutting: This is also called flame cutting. It is similar to oxygen torch cutting only that the source of ignition here is a laser beam. It is mostly used for cutting carbon steels of more than 1mm thickness.
It is basically how the laser beam is moved over the material being cut. Laser cutting machines can be configured as flying optics, moving material, and hybrid systems. The motion axes are designated X and Y or Z if the cutting head can be controlled.
In spite of the high power consumption by laser machines, laser cutting produces precise, clean and uncontaminated products.