Trends In Tool Coating Technology

1. Coating composition will tend to be diversified and compounded

    The first generation of PVD coatings mainly consisted of TiN, on the basis of which a variety of single metal coatings such as TiC, TiCN, ZrN, CrN and WC were developed. Along with the further development of PVD deposition technology, aluminium element technology has been added to the coating, and multi-metal alloy coatings containing aluminium, such as TiAIN and TiAICN, have been introduced one after another, whose wear resistance and red-hardness are much higher than those of single-metal coatings, and can be used for higher cutting speed, such as rolling cutting, which can reach 150m/min.

2. Application development of coatings is becoming more targeted

    To meet the requirements of different applications, coatings are increasingly being developed and designed in a targeted manner. For different application areas such as drilling, milling, dry rolling, stamping, drawing, etc., coatings with relative advantages in this area are being developed in response to the characteristics and properties required.

3. Deposited particles for coatings tend to be nanosized

 With the development of nanotechnology and the advancement of coating technology, nano tool coatings have also attracted the attention of a wide range of researchers and PVD coating service companies. Nanosizing the deposited particles of coatings enhances the bond strength between the coating and the substrate as well as between the layers, while reducing the surface roughness of the coating. Currently, most coatings still have large deposited particles, and although there are coatings known as nanoscale, larger particles can still be found on the final surface of the coating and the coating surface is still rougher. Reducing the size of deposited particles in coatings and keeping the process stable to avoid large abnormal particles will be another direction for coating development.

4. Lower and lower process temperatures for coatings

  From a deposition temperature of around 1000°C for general CVD coatings to a deposition temperature of around 500°C for PVD and PECVD coatings, the deposition temperature of the coatings has been reduced and therefore the application range of the coatings has been expanded. However, deposition temperatures of around 500°C can still have adverse effects on the coated workpiece, such as deformation and reduced substrate hardness. Therefore, special requirements need to be placed on the pre-treatment of the coated workpiece, e.g. the tempering temperature of the workpiece must not be lower than the coating temperature. Lower temperature coatings, e.g. below 200°C, will remove these restrictions, allowing a wider range of materials to be used for the coating, a more flexible choice of pre-treatment, and a more viable integrated application of different surface modification techniques. The application of low temperature coatings will also reduce the energy consumption of the coating equipment and have a certain environmental impact in terms of energy savings. In addition, the reduction of coating temperature makes the heating and cooling time reduced will also shorten the delivery cycle of the coating, more efficient, so, low temperature coating will greatly promote the application of coating, popular, will become the development of PVD coating, an important direction.