Surface Superhardening Technology of Metal Mold


Release time:

2022-08-30

1. Technical Introduction
Diffusion metal carbide coating technology is the workpiece placed in a special medium, the role of diffusion on the surface of the workpiece to form a layer of microns to tens of microns of metal carbide layer.
The carbide layer has extremely high hardness, HV can reach 1600~3000 (determined by the type of carbide). In addition, the carbide layer is metallurgically combined with the substrate, which does not affect the surface finish of the workpiece, has extremely high wear resistance, anti-seizure (bonding), corrosion resistance and other properties, and can greatly improve the service life of tools, molds and mechanical parts.
  
2. Comparison with related technologies
The method of forming a super-hard compound film on the surface of the workpiece is an effective and economical method to greatly improve its wear resistance, anti-seizure (anti-bonding), corrosion resistance and other properties, thereby greatly improving its service life. At present, the surface superhardening treatment methods of the workpiece mainly include physical vapor deposition (PVD), chemical vapor deposition (CVD), physical chemical vapor deposition (PCVD) and diffusion metal carbide cladding technology. Among them, PVD method has the advantages of low deposition temperature and small deformation of the workpiece. However, due to the poor bonding force between the film layer and the substrate and the poor process winding, it is often difficult to give full play to the performance advantages of the superhard compound film layer. CVD method has the outstanding advantages of good film-base bonding force and good process winding and plating, but for a large number of steel materials, its subsequent matrix hardening treatment is more troublesome, a little careless, the film layer is easy to destroy. Therefore, its application is mainly concentrated in hard alloy and other materials. PCVD deposition temperature is low, the film-based binding force and process around the plating are compared with the PVD method has a greater improvement, but compared with the diffusion method, the film-based binding force is still a large gap, in addition, because the PCVD method is still plasma film, although the around plating is improved compared to the PVD method, but can not be eliminated.
The metal carbide coating formed by the diffusion method metal carbide coating technology forms a metallurgical bond with the substrate, and has a film-substrate bonding force that PVD and PCVD cannot match. Therefore, the technology can really give full play to the performance advantages of the super-hard film. In addition, the technology does not have the problem of winding and plating, and the subsequent substrate hardening treatment is convenient and can be repeated many times, making the applicability of the technology more extensive.
  
3. Technical advantages
Diffusion metal carbide coating technology is widely used in Japan, European countries, Australia, South Korea and other countries. According to the survey, many imported equipment on the supporting mold a large number of the use of the technology, these molds in the localization, due to the lack of the corresponding mature technology, often make the mold life is low, some even can not be localized.
This technology has been studied in China in the 1970 s, but due to the limitations of various conditions, the process and equipment are often difficult to pass the test of batch and long-term production, so that some actual problems in this technology are not easy to expose or difficult to solve, and often give up halfway. In the process of more than ten years of research and application, we have conducted in-depth research on the actual problems of the technology and equipment, and made effective improvements. The improved technology and complete sets of equipment have been able to meet the requirements of long-term stable production. The life level of the processed mold has reached the life level of the imported similar mold, and has obtained rich production experience in the practical application of various molds, it has laid a solid technical foundation for the large-scale popularization and application of this technology.