The traditional cutting technologies include flame cutting, plasma cutting, water cutter cutting, wire cutting and punch machining, etc. as a new technology in recent years, laser cutting is to irradiate the laser beam with high energy density on the workpiece to be processed, to heat and melt the local part, and then blow the slag to form a cutting seam with high pressure gas.

Compared with other thermal cutting methods, laser cutting is characterized by high cutting speed and quality. It can be summarized as follows.            

(1) good cutting quality           

Because of the small laser spot, high energy density and fast cutting speed, laser cutting can obtain better cutting quality.            

① The laser cutting cuts are thin and narrow, both sides of the cutting seam are parallel and perpendicular to the surface, and the dimension accuracy of the cutting parts can reach ± 0.05mm.            

② The cutting surface is clean and beautiful, and the surface roughness is only tens of microns. Even laser cutting can be used as the last process, without machining, and parts can be used directly.            

③ After laser cutting, the width of the heat affected zone is very small, and the performance of the material near the cutting seam is almost unaffected. Moreover, the deformation of the workpiece is small, the cutting accuracy is high, the geometry of the cutting seam is good, and the cross section of the cutting seam presents a regular rectangle. The comparison of laser cutting, oxyacetylene cutting and plasma cutting methods is shown in Table 1. The cutting material is 6.2mm thick low carbon steel plate.            

(2) high cutting efficiency due to the transmission characteristics of laser, laser cutting machine is generally equipped with multiple CNC worktables, the whole cutting process can be fully CNC. During the operation, only changing the numerical control program can be applied to the cutting of parts with different shapes, which can not only carry out two-dimensional cutting, but also realize three-dimensional cutting.            

(3) fast cutting speed            

The laser power of 1200W is used to Cut 2mm thick low carbon steel plate, the cutting speed can reach 600cm / min; the cutting speed of 5mm thick polypropylene resin plate can reach 1200cm / min. The material does not need to be clamped and fixed in laser cutting, which not only saves the fixture, but also saves the auxiliary time of loading and unloading.            

(4) non contact cutting            

During laser cutting, the cutting torch has no contact with the workpiece, and there is no tool wear. When machining parts with different shapes, it is not necessary to change the "tool", but only to change the output parameters of the laser. The laser cutting process has low noise, small vibration and no pollution.            

(5) there are many kinds of cutting materials            

Compared with oxyacetylene cutting and plasma cutting, there are many kinds of laser cutting materials, including metal, non-metal, metal and non-metal matrix composite materials, leather, wood and fiber, etc.            

(6) disadvantages: due to the limitation of laser power and equipment volume, laser cutting can only cut medium and small thickness plates and pipes, and with the increase of workpiece thickness, the cutting speed decreases significantly. The cost of laser cutting equipment is high and the one-time investment is large.