Tools that undergo aggressive operations demand long-lasting, durable surfaces in order to produce high quality results every time. It has been said that tool coatings can help extend tooling life by a significant amount, and some procedures would be difficult to do without them. Here are a few coatings that can improve tooling life:
Titanium Nitride (TiN)
This coating is perfect for High Speed Steel (HSS) tooling as its general purpose PVD coating increases hardness; the harder the material/surface, the longer the tool will last and the faster it will be able to run. It also provides a high oxidation temperature which means that they will work better in high heat applications, by transferring the heat away from the tool onto the part.
Titanium Carbo-Nitride (TiCN)
Also ideal for HSS tooling, this coating has the addition of carbon so, hardness is increased even more and surface lubricity is significantly improved. Friction between the tools, the surface and the material can lead to a shorter coating life, but with this higher surface lubricity, less heat is generated and speeds are increased to avoid friction altogether.
Titanium Aluminium Nitride (TiALN or ALTiN)
High Speed Machining (HSM) benefits the most from this tool coating. Once applied, a layer of aluminium oxide is formed around the surface area of the tooling which means that it will last longer in high heat applications. When little to no coolant is being used, this is the best means of protecting and improving your tooling life.
Chromium Nitride (CrN)
Chromium Nitride is best used for tooling that comes into contact with Built Up Edge (BUE); this coating has anti-seizure properties which prevents chemical reactivity between the tool and the cutting material. With BUE, the tool can get chipped or the part oversized, so this almost invisible coating will protect the equipment.
This is only a selection of the various types of tool coatings there are, multi-layer coatings are available too. If you decide to invest in tool coating, remember that you are slightly modifying the tooling material, so you need to figure out the best lubrication for it as well. This also protects tooling life as it creates a barrier between the tools and the metal.