Views: 8989 Author: heyu Publish Time: 02-21-2020 Origin: Site
Small deformation of workpiece with narrow slit
The laser beam is focused into a very small light point, which makes the focal point reach a high power density. At this time, the heat input by the beam far exceeds the part reflected, conducted or diffused by the material. The material is soon heated to the extent of vaporization, and the vaporization forms a hole. With the relative linear movement of the beam and the material, the slit with narrow width is formed continuously. The heat effect of trimming is very small, and there is basically no workpiece deformation.
In the cutting process, the auxiliary steam body suitable for the material to be cut is also added. During steel cutting, oxygen is used as the auxiliary material to generate exothermic chemical reaction oxidation between steam and molten metal, and at the same time, it helps blow away the slag in the slit. For cutting polypropylene, compressed air is used, and inert gas is used for cutting cotton, paper and other flammable materials. The auxiliary vapor entering the nozzle can also cool the focus lens, prevent smoke from entering the lens base to pollute the lens and cause the lens to overheat.
Most organic and inorganic materials can be cut by laser. In the heavy metal processing industry, many metal materials, regardless of their hardness, can be cut without deformation. Of course, for high reflectivity materials, such as gold, silver, copper and aluminum alloy, they are also good heat transfer conductors, so laser cutting is very difficult or even impossible. Laser cutting has no burr, wrinkle and high precision, which is superior to plasma cutting. For many mechanical and electrical manufacturing industries, because the modern laser cutting system controlled by computer program is convenient for cutting workpieces of different shapes and sizes, it is often preferred over punching and pressing processes; although its processing speed is slower than die punching, it has no die consumption, no need to repair the die, and it also saves the time to replace the die, thus saving the processing cost and reducing the production Production cost, so it is more cost-effective on the whole.
Non contact machining
After focusing the laser beam, a very small point of action with very strong energy is formed. First of all, the laser light energy is converted into amazing heat energy and kept in a very small area, which can provide (1) a narrow straight edge slit; (2) a minimum heat affected area adjacent to the edge cutting; (3) a very small local deformation. Secondly, the laser beam does not exert any force on the workpiece, it is a non-contact cutting tool, which means that (1) the workpiece has no mechanical deformation; (2) there is no tool wear, and there is no tool conversion problem; (3) the cutting material does not need to consider its hardness, that is, the laser cutting ability is not affected by the hardness of the material being cut, and any hardness material can be cut. Thirdly, the laser beam has strong controllability, high adaptability and flexibility, so ⑴ it is convenient to combine with automation equipment, and it is easy to realize the automation of cutting process; ⑵ because there is no restriction on cutting workpiece, the laser beam has infinite profiling cutting ability; ⑶ it can combine with computer to arrange the whole sheet and save materials.
Adaptability and flexibility
Compared with other conventional machining methods, laser cutting has greater adaptability. First of all, compared with other thermal cutting methods, other methods can not act on a very small area like laser beam, resulting in wide incision, large heat affected area and obvious workpiece deformation. Laser can cut nonmetal, but other thermal cutting methods can't.
Generally speaking, the quality of laser cutting can be measured by the following six standards.
1. Cutting surface roughness Rz
2. Size of slag hanging on the incision
3. Perpendicularity and slope of trimming u
4. Cutting edge fillet size R
5. Stripe drag n
⒍ flatness f
