The main component of automotive molds is the cover mold, which is the general name for the molds used to make all the parts on the car. The take-off of the domestic automobile industry has brought a broad space for the development of automotive molds, and has higher requirements for automotive molds.

1. A coating that solves all cutting problems has been rejected

In recent years, the rapid development of China's automobile manufacturing industry has also benefited the tool industry for the automotive industry and the tool coating manufacturing industry that is indispensable for tool manufacturing. The automobile manufacturing industry is the first in China to accept pvd coatings.

In order to adapt to the rapid development of the automotive industry, tool coatings are constantly emerging with new coating varieties, improved coating quality and more targeted individualized coating development. Today's tool coatings are not only rich in variety, but also more specialized. In the past, the idea that a coating can solve all cutting applications has gradually been replaced by the more scientific application of choosing the right coating. The domestic automotive industry is an important indicator of the maturity of its choice and application of tool coatings.

2. Why do the molds have to be coated?

With the increasingly fierce competition in the automotive industry and the increasingly harsh economic conditions, auto parts manufacturers are paying more and more attention to production costs. A large part of the cost of parts production comes from the cost of the tool, and the mold is one of the most important parts. Due to its long production cycle and high processing precision, the molds are expensive, so manufacturers always hope that the mold life can be long enough, and good molds should ensure the surface quality of the products in the process of processing products. Reasonable application of surface treatment technology to obtain high-precision mold surface is a necessary condition for improving product precision and surface quality.

Among the many surface treatment methods, PVD coating is undoubtedly the preferred method to solve the above problems. PVD coating technology is one of the latest and most advanced surface engineering technologies. It is a surface coating technology that uses arc discharge as a source of metal evaporation. Because the arc ion plating technology has the characteristics of high coating speed, dense film layer and good adhesion of the film, the application of arc ion plating in the field of super hard coating of the mold is more and more extensive, and will occupy an increasingly important position.

From the cost point of view, the investment in PVD coating is less than one-tenth of the cost of the mold, but the life and the surface quality of the machined part can be significantly improved.

Compared with the traditional surface heat treatment method, the surface hardness of the general PVD coating is several times to several tens of times higher, which makes the life of the PVD-treated mold increase several times to several tens of times. From the perspective of service life, the cost of the tool is greatly reduced. As the life of the mold increases, the impact of machine downtime on the replacement of the mold is greatly reduced. Generally, PVD coatings have much lower friction coefficient than ordinary metal materials due to their own characteristics. For example, the surface friction coefficient of the surface-polished metal material is generally about 0.9, and the coefficient of friction of the PVD coating material to the steel is between 0.1 and 0.6. The smaller coefficient of friction of the different coatings reduces the surface friction of the PVD-treated mold during processing with the surface of the part being machined, and the surface quality of the part is much better than that of the part produced without the coated mold.

3. The wear mechanism of the mold determines the application type of the coating.

Due to different types of molds, the products produced are different and the form of failure is different. For example, during the normal use of the blanking die, the edge wear of the die due to friction is the main failure mode, and the wear mechanism is analyzed. The wear of the convex and concave die is mainly the adhesive wear and the abrasive wear.
4. Common coating types on the market

At present, the common types of tool coatings on the market are the first aluminum nitride TiAlN. The reason for this is that TiAlN has higher hardness and better high temperature performance. It can be used to cut harder alloy steels and is suitable for high speed and dry cutting, which is especially important for modern automotive manufacturing that pursues high efficiency. The TiAlN composite coating with TiAlN as the main component has higher thickness and better bonding with the tool base than the single TiAlN coating, so the coating is suitable for heavy cutting.

In contrast, TiN coatings are currently only used in low-speed and low-volume cutting processes due to their heat-resistant temperatures (generally below 600 oc) and low hardness (generally below hv2000).

Although TiAlN exhibits outstanding performance in the cutting of carbon steel and alloy steel, there is no advantage in the cutting of non-ferrous metals such as aluminum alloys. The actual cutting shows that if the tool with TiAlN coating is applied to the cutting of aluminum alloy, it can not only improve the processing performance, but also cause the tool to be scrapped early due to poor chip removal, and also causes defects such as increased roughness of the machined surface. In this regard, European and American companies are now widely adopting a new generation of coatings to solve such processing problems. These marketed coatings are diamond-like coatings (DLC coatings) and tantalum nitride-based aluminum-free coatings. Coating - ZrN composite coating.
Automotive stamping tooling (TiN, TiCN):

Solve the wear of the adhesive and improve the life of the mold;

Avoid product strain and improve production efficiency;

Automotive Die Casting Mould (AlCrN, AlTiN):

Solve the problem of sticking and erosion of adhesives in aluminum alloy die casting;

Prevent the mold from being thermally cracked, deformed, etc.;

Automotive forging die (AlCrN, TiAlN-ML):

Solve the wear of the adhesive and improve the life of the mold;

Solve the hot crack problem.

All in all, China's automobile manufacturing industry has played a very important role in bringing pvd coating technology to China. At the same time, both internationally renowned coating companies and local coating suppliers have provided domestic automotive manufacturing development in recent years. Strong support, this mutually reinforcing relationship will be further consolidated and upgraded in the future development!