Common cutting tool coatings are introduced

Proper surface treatment can improve cutting tool life, reduce processing cycle time and improve surface quality. In the process of machining, we need to choose the right coating according to the processing needs. Every characteristic of the coating plays a very important role. The following is an introduction to several commonly used coatings:

1. Titanium Nitride Coating (TiN)

TiN is a universal PVD coating, which can improve cutting tool hardness and have higher oxidation temperature. The coating can be applied to high speed steel cutting tools or forming tools to obtain good machining results.

2. Titanium nitride carbide coating (TiCN)

TiCN coating is an ideal coating for HSS tools because of the addition of carbon to improve tool hardness and obtain better surface lubricity.

3. TiAlN/AlTiN coating

The alumina layer formed in the TiAlN/AlTiN coating can effectively improve the high temperature machining life of the tool. The coating can be used for carbide cutting tools mainly used for dry or semi-dry cutting. Depending on the proportion of aluminum and titanium contained in the coating, AlTiN provides a higher surface hardness than TiAlN, making it another viable coating option for high-speed machining.

4. Chromium nitride coating (CrN)

The CrN coating's excellent adhesion resistance makes it the preferred coating for processing where it is prone to chip formation. With this almost invisible coating, the workability of HSS or carbide tools and forming tools will be greatly improved.

5. Diamond coating

CVD diamond coating provides the best performance for machining tools for non-ferrous metal materials and is ideal for machining graphite, metal matrix composites (MMC), high silicon aluminum alloys and many other high abrasive materials (note: A pure diamond-coated tool cannot be used to process steel, because it generates a lot of cutting heat and causes a chemical reaction that destroys the adhesive layer between the coating and the tool.

Coatings suitable for hard milling, tapping and drilling are different and each has its own specific application. In addition, multilayer coatings can be used with additional coatings embedded between the surface and the tool matrix to further improve cutting tool life.