By forming layer of high hardness and high wear resistance onto molds surface, the dies can be improved performances of wear resistance, seizure resistance, corrosion resistance, etc. So it is an efficient and economic way to increase dies life. For example, the hardness of vanadium carbide layer caused by TD coating can reach about 3000HV. The hardness is more than hardness of nitriding coating, carburizing coating, and boronizing coating. So the TD coating has better wear resistance.
Hardness contrast in different processes

Chromium plating and nitriding including gas nitriding, ion nitriding, soft gas nitriding, salt bath soft nitriding(QPQ) are two widely application ways. But their wear resistances are limited under severe condition compare with TD coating. On the other hand the chromium plating weakly bind onto substrate, so it easy peel. If the coating peels or wears out, that means the all good effects are lost.

Physical vapor deposit, physical vapor deposit, chemical vapor deposit, TD coating are modern surface treatment technologies. The hardness of coating of TiN or TiCN during PVD or PCVD process can reach 2000-3000HV, even more, with low treatment temperature and little distortion. These technologies are widely applied in decoration industry and cutting tools industry. Because the coating formed by these two technologies, weakly binding onto the substrate, it easy peels in practical applications compare with TD coating. If there is severe condition like drawing, these two technologies can get reluctance results, even failure results.

The coating hardness of CVD with high temperature is similar to TD coating hardness, and both coatings are metallurgy bind onto substrate. The binding force between CVD coating and substrate is far stronger than PVD or PCVD. The CVD is one of the best surface harden method. But the CVD cost is high, and serious post treatments are very trouble. So the CVD is major used in cement carbides. The post treatments of TD coating are very easy. It is not only used in steel, but also used in cement carbides, and it can be repeat applied.

Regarding galling resistance, all the above technologies are excellent. Just difference wear resistance and binding force will affect on practical application. Comparing with other technologies, TD coating, CVD with high temperature, and using cement carbides are the best methods for galling. If you are interested in details, please refer to our related article.

 

 

Announcement

Different technologies have their own advantages and disadvantages. As their application situations are different, regarding definite technology as best one depending on one or two parameters is unscientific. Which material and surface treatment we should take must depend on definite application. With high temperature treatment, TD coating has its own advantages and disadvantages. According to our experience, the professional guidance and good cooperation are necessary in order for TD coating to succeed. Otherwise there is big risk.