Cutting tools

PVD coatings for cutting tools

The introduction of PVD [relevant-to-adsense type=”start”]thin film coatings[relevant-to-adsense type=”stop”] for cutting tools in the metal cutting industry is one of the main success stories in the industrial application of modern coating technology over the last 30 years. The first PVD coating material to have a commercial application on cutting tools was TiN in the early 1980s and since the 1990s most cutting tools are PVD coated particularly in applications where sharp edges are required, e.g. threading, grooving, end-milling, etc. and in cutting applications that have a high demand for a tough cutting edge, e.g. drilling. In solid carbide cutting tools (end-mills and drills) PVD is the standard coating technology. The TiAlN PVD coating is currently the most widely deposited PVD coating for cutting tools but other coatings such as TiCN and CrN offer better solutions in certain applications.

Saves companies billions
In the areas of machining and tooling PVD coatings are widely used to increase the life and productivity of production cutting tools saving companies billions of dollars worldwide. The use of PVD coatings on cutting tools saves money in three ways.

Run tools faster
Firstly PVD coated cutting tools can be run faster reducing cycle times and enabling the production of more components in less time.

Reduce wear and pickup
In metal cutting different wear processes exist depending on the workpiece material. These wear mechanisms include abrasive wear on the flank and clearance face of the cutting tool, crater wear on the rake face, caused by chemical interaction between the cut chip and the tool surface, built-up edge on the cutting edge and depth-of-cut notching caused by abrasion by the outer edge of the chip.

None of these wear mechanisms exists in isolation however one usually predominates. For example when cutting low-silicon aluminum a built-up-edge is generated that affects the quality of the finished product whereas high-silicon aluminum causes the tool to wear predominantly due to abrasion.

PVD coatings are resistant to all forms of wear increasing the life of cutting tools reducing tool-changing costs.

Reduce the need for cutting fluid
Cutting fluids cost companies today up to 15% of their total production costs. High speed cutting and dry machining involve extremely high temperatures at the cutting edge. PVD coatings such as TiAlN have incredible thermal stability, hot hardness and oxidation resistance. PVD coatings can therefore be run dry or with very limited amount of cutting fluid.

Cut hard materials
PVD coated cutting tools can cut extremely hard materials e.g. 63 HRC.

Re-sharpening and re-coating of cutting tools
Companies such as Unimerco offer a re-sharpening and re-coating service for cutting tools. The cutting tools achieve the same performance as new coated tools.

Example drill and milling cutter sets for sale