The middle speed wire edm machining belongs to the category of reciprocating high-speed wire EDM machine tools, which realizes multiple cutting functions on the high-speed reciprocating wire EDM machine. The middle speed wire edm machining has the advantages of fast and slow wire cutting, but it is necessary to pay attention to the deformation treatment during the cutting process. The thermal stress generated by the workpiece during cutting will cause non-directional and irregular deformation of the material, resulting in uneven cutting and falling and affecting the cutting accuracy. Therefore, during the cutting process, different machining allowances must be reserved according to different materials to fully release the internal stress and deformation. It is commonly used for the parts production, which need good surface and cheap cost.
The low speed wire edm machining is generally 0.2m/s, and the accuracy is up to 0.001mm. Usually, copper wire is used as the electrode wire. The electrode wire moves in one direction at a low speed, and the quality of the machined surface is close to the grinding level. The low speed wire edm machining adopts the method of continuous wire feeding of electrodes, and the electrodes can be supplemented when they are lost, so the machining accuracy can be improved. The surface roughness value of the workpiece processed by WEDM can generally reach Ra0.8μm and above, and the roundness error, linear error and dimensional error are smaller than those of WEDM. It is commonly used for moulds production.
The material to be cut is irradiated with a high power density laser beam, so that the material is quickly heated to the vaporization temperature and evaporated to form holes. Complete the cutting of the material.
A laser beam with high energy density is used to heat the workpiece, so that the temperature rises rapidly, reaching the boiling point of the material in a very short time, and the material begins to vaporize to form vapor. These vapors are ejected at a high velocity, and at the same time as the vapors are ejected, cuts are formed in the material. The vaporization heat of the material is generally large, so a large power and power density are required for laser vaporization cutting.
When laser melting and cutting, the metal material is melted by laser heating, and then non-oxidizing gas (Ar, He, N, etc.) is sprayed through a nozzle coaxial with the beam, and the liquid metal is discharged by the strong pressure of the gas to form a cut. Laser melting cutting does not need to completely vaporize the metal, and the energy required is only 1/10 of the vaporized cutting. Laser melting cutting is mainly used for cutting materials that are not easily oxidized or active metals, such as stainless steel, titanium, aluminum and their alloys.
The principle of laser oxygen cutting is similar to that of oxyacetylene cutting. It uses a laser as a preheating heat source and an active gas such as oxygen as a cutting gas. On the one hand, the blown gas acts on the cutting metal to produce an oxidation reaction, releasing a large amount of oxidation heat; on the other hand, the molten oxide and molten material are blown out from the reaction zone to form a cut in the metal. Since the oxidation reaction in the cutting process generates a lot of heat, the energy required for laser oxygen cutting is only 1/2 of that of melting cutting, and the cutting speed is much higher than that of laser vaporization cutting and melting cutting. Laser oxygen cutting is mainly used for easily oxidized metal materials such as carbon steel, titanium steel and heat-treated steel.
Laser scribing uses a high-energy-density laser to scan the surface of a brittle material, so that the material is heated and evaporated to form a small groove, and then a certain pressure is applied, and the brittle material will crack along the small groove.
Compared with other thermal cutting methods, laser edm machining generally characterized by fast cutting speed and high quality. Specifically summarized in the following aspects.
In this case, the cut edge will not be oxidized. For plates with a thickness of more than 10mm, using a special plate for the laser and applying oil to the surface of the workpiece during processing can get better results.
Copper and brass can only be cut if a “reflection absorber” device is installed on the system. Otherwise reflections can destroy optical components.
Both wire edm machining and laser edm machining are good for production, they can help you to speed up the production and save the cost. You can choose the better one to use in your production.