Mold processing technology and development

In modern production, molds are important process equipment for the production of various industrial products. With the development of modern industry and cutting-edge science and technology, people have higher and higher requirements for the mold industry because they directly determine the quality, cost, and service life of their associated products. According to the HC Surface Finishing Network Xiaobian, how to improve the quality, service life, and production cost of the mold has become an urgent problem to be solved. For those molds that are used under high temperature conditions and require wear and oxidation resistance, surface treatment is a commonly used process for improving surface properties. It is the most effective way to increase the quality and service life of molds and reduce costs, and to improve mold quality. It is of great significance to significantly reduce production costs, increase production efficiency, and fully exploit the potential of mold materials.

The mold surface treatment technology and the development of the mold in the work in addition to requiring the substrate to have a reasonable enough strength and toughness of the fit, the surface properties of the mold's performance and service life is essential. These surface properties refer to: wear resistance, corrosion resistance, friction coefficient, fatigue properties, and the like. The improvement of these properties depends on the improvement and improvement of the matrix material. It is very limited and uneconomical. However, surface treatment technology can often achieve a multiplier effect. This is the reason why the surface treatment technology has developed rapidly.

The surface treatment technology of the mold is a systematic project to change the morphology, chemical composition, structure and stress state of the mold surface to obtain the required surface properties through surface coating, surface modification or composite processing technology. From the surface treatment methods, it can be divided into: chemical methods, physical methods, physical and chemical methods and mechanical methods. Although new processing technologies aiming at improving the surface properties of molds are emerging, the main applications for mold manufacturing are nitriding, carburizing, and hardened film deposition.

The nitriding process includes gas nitriding, ion nitriding and liquid nitriding. In each nitriding method, there are several kinds of nitriding techniques that can adapt to the requirements of different steel workpieces. Because the nitriding technology can form a surface with excellent performance, and the nitriding process has good coordination with the quenching process of the die steel, and at the same time the nitriding temperature is low, the nitriding needs no intense cooling, and the deformation of the die is minimal, so the die Surface strengthening is the use of nitriding technology earlier, but also the most widely used.

The purpose of carburizing the mold is mainly to improve the overall toughness of the mold, that is, the working surface of the mold has high strength and wear resistance, and the technical idea introduced thereby is that the lower level material is used, that is, quenching through carburizing. Instead of higher grade materials, manufacturing costs are reduced.

Hard film deposition technology is currently more mature CVD, PVD. In order to increase the bonding strength of the film surface, a variety of enhanced CVD and PVD technologies have been developed. The hardened film deposition technology was first applied to tools (tools, cutting tools, measuring tools, etc.), and the effect was excellent. A variety of tools had applied a cured film as a standard process. Dies have been coated with hardened film technology since the 1980s. Under the current technical conditions, the cost of hardened film deposition technology (mainly equipment) is high, and it is still only applied to some precision and long-life molds. If the method of establishing a heat treatment center is adopted, the cost of coating the cured film will be greatly reduced. More molds using this technology can improve the overall level of mold manufacturing in China.

The surface treatment technology has been widely applied to molds. Significant progress and huge economic benefits have been achieved in improving mold life and product quality. However, there are still some gaps in the application and development of advanced surface technologies compared with foreign countries. The full application of surface treatment technology is an important economic and efficient means of improving the life of the mold, and is also the only way to develop modern molds. Research and development of surface treatment techniques for precision, large-scale molds is the key to the development of mold surface technology. And difficulties.

Development prospects of mold surface treatment technology The application of surface treatment technology to the mold surface has, to a considerable extent, compensated for the defect of the mold material, which can achieve the following effects:

(1) Improve the surface hardness, wear resistance, corrosion resistance and high temperature oxidation resistance of the mold, and greatly increase the service life of the mold;

(2) Improve the scratch resistance and mold release ability of the mold surface and increase productivity;

(3) Molds made of carbon tool steel or low-alloy steel, after being surface-strengthened, can achieve or exceed the surface properties of high-alloyed mold materials, and even reach the performance index of cemented carbide, not only greatly reducing the cost of materials. , And simplify the mold manufacturing process and heat treatment process, reduce production costs;

(4) It can be used for the repair of molds. For example, the brush plating technology can complete the repair of the mold surface without disassembling the mold, and can guarantee the quality of the mold surface after repair.

For traditional surface technologies, the effects of treatment should be further improved and the energy consumption and environmental pollution should be reduced. Extend the composite form between traditional surface technology and modern surface treatment technology, combining nanotechnology and mold surface technology. Xu Binshi, an academician of the Chinese Academy of Engineering, has done a lot of research work on nano-thermal spray technology, nano-composite plating technology, and nano-metallization on the surface of metal materials, and achieved good results.

According to the HC Surface Treatment Editor, most of the surface treatment technologies currently require large-scale specialized equipment and the cost is high. Therefore, they are still only applied to some precision and long-life molds. Combined with the structural characteristics of China's current mold manufacturing industry, in addition to continuing to improve the existing mold surface treatment process, it should also study and develop low-cost mold surface treatment technology, and further expand the application of mold surface treatment technology to improve our country's overall Mold manufacturing level.