Application of EDM technology in electric machining in mold manufacturing (2)

Third, the application of EDM technology in mold processing

Due to the rapid development of the mold industry, in order to meet the needs of some special situations, a large number of mold materials with high strength, high hardness, high toughness, high brittleness, high temperature resistance and other special properties have been successively produced, thus bringing traditional metal cutting processing. Many new difficulties and problems are difficult to meet the requirements with traditional processing methods. At this time, EDM technology is widely used and mold processing. With the application of EDM technology to the mold industry, it has had a great impact on the traditional mold processing technology and changed the mold processing process. The conventional processing method is to perform milling after annealing; then heat treatment, grinding or electric discharge machining; finally, manual grinding and polishing, and the processing cycle is long. Dies are often scrapped due to quenching or cracking. The EDM technology can process the quenched template to avoid hot deformation defects and inlay structure, which not only simplifies the mold structure, but also improves the strength and life of the mold.

The electric spark modification technology has great application on the surface of the mold. In order to improve the quality of the mold surface, the working principle of high temperature is generated by electric spark pulse discharge. The hard alloy material such as YG8 is used as the electrode material to infiltrate the hard alloy material. On the working surface of the mold and wearing parts, a hard white alloy strengthening layer with high hardness, high strength, high wear resistance, high temperature resistance and no peeling is formed to change the physical and chemical properties of the surface. A very effective method of surface treatment. The electric spark strengthening layer is a new alloy layer formed by re-alloying the electrode and the workpiece material under high temperature and high pressure at the moment of discharge, and is not simply coating and stacking of the electrode material. A diffusion layer of nitrogen or the like between the alloy layer and the base metal is firmly bonded to the substrate and is extremely resistant to impact. In the intensive treatment, since the discharge time is very short, the area of ​​the discharge point is small, the thermal effect of the discharge only occurs in a small area on the surface of the workpiece, and the whole workpiece is still at a normal temperature state or the temperature rise is low, the workpiece is in a cold state, and the time is short. Does not cause annealing or thermal deformation. EDM modification is carried out in an air or liquid medium. It can be applied to the local surface of the part, as well as to the modification of the plane or surface of the general geometry, such as tools, molds, mechanical parts and so on. The electrode material can be freely selected according to the application. When repairing the worn machine parts, carbon, copper, brass and other materials can be used as the electrodes. These materials are widely used and the material consumption is also small. The modified layer of different thicknesses and surface roughness can be obtained by adjusting the electrical parameters and controlling the modification time. The method of operation is easy to master and does not require an operator with a high level of skill. It can use a small amount of material to achieve the effect that a large amount of expensive overall material is difficult to achieve, which can improve the hardness, wear resistance and high temperature red hardness of the product, significantly improve the service life of the product, and greatly reduce the precious material. Consumption, reducing production or maintenance costs.

The precision of EDM precision cavity mold is represented by three aspects: dimensional accuracy, profiling precision and surface quality. Processing precision cavity molds. The dimensional requirements of each part should be correctly analyzed, and the dimensional accuracy of different places should be flexibly controlled. Special attention should be paid to those parts with high dimensional requirements. The important dimensional tolerances in precision cavity molds can reach ±2~3 microns, which shows the strictness of dimensional requirements. The precision of the profiling is also high, and the cavity should be clear and the edges and corners are clear. The surface roughness value is uniform and reaches the predetermined surface roughness value. Generally, the Ra value is required to be small, and even the mirror surface processing is required, and the thickness of the surface deterioration layer of the EDM portion is small.

Fourth, summary

Nowadays, with the rapid development of the economy, the great potential of EDM technology and the production potential has become an important technical field for the research of Germany, the United States and Japan. High-speed machine tools have also entered the market and are used in aircraft, automotive and mold manufacturing industries. However, in the mold industry, EDM technology has many factors affecting the quality of machining in the process of EDM. In the specific processing, it should be reasonable according to the processing requirements of the workpiece, the material of the electrode and the workpiece, and the processing index. Select processing parameters, and master the conversion rules through process testing and production practices to improve mold processing accuracy, processing productivity and economy. If these problems are solved properly, I believe that in the near future, EDM technology will have more and more applications in the mold industry, and it has more and better prospects.

Webbing Belt

Webbing Belt,Elastic Webbing Belt,Army Webbing Belt

Dacheng Advanced Material Co., Ltd. , http://www.bullet-proofs.com