Why You Need TiAlN Coated End Mills

[Geoffrey Less]

End mills are extremely useful tools, but they can easily become worn out from extensive milling. Between the natural fatigue to cutting edges and the stress of the heat that comes with high speed machining can easily cause premature tool failure. In order to better protect their tools, many manufacturers offer options that have been treated with specialized coatings like Zirconium Nitride(ZrN) and Titanium Aluminum Nitride(TiAlN). TiAlN coated end mills and drill bits offer a much longer lifespan and edge retention when compared to uncoated tools.

The highest quality end mills are manufactured from solid carbide stock. Tool carbide is a mixture of powdered carbide ceramic and a binding metal, typically cobalt. This material is particularly well suited for end mills because it is both extremely rigid and holds an edge remarkably well. Other end mill materials like high speed steel alloys are able to maintain hard edges even at high temperatures, but they can still lose their temper. Because the edge strength of carbide tools is the result of the material’s ceramic content, high temperatures will not significantly impact their ability to hold their cutting edges.

Despite these advantages over conventional solid metal tools, carbide tools can still suffer from heat fatigue. When operating at high speeds, especially over long periods of time, your carbide tools will wear down. This typically takes longer than comparable steel tools, but it can affect your productivity if you experience a sudden tool failure or you are working with tools that are not sufficiently sharp. One way to extend the working life of your tools is to purchase options that have been treated with a protective coating.

One of the most popular tool coatings for extending the working life of milling cutters is TiAlN. This material is deposited onto tools using specialized vapor deposition processes where the coating material is vaporized and then resolidified on the surface of the tool to create a thin, consistent, and extremely secure coating. These coatings are typically only one micron thick and manage to provide protection against heat by creating an insulating layer of aluminum oxide on the surface of TiAlN coated end mills.

This layer of Al2O3 helps to deflect heat into the chips and away from the body of the cutter. The coating itself is also very hard, which helps maintain sharp edges and avoid breakage. It has even been shown that TiAlN coatings can continue to get harder over time as the tools are continuously heated. This makes them a great option for any tool that is regularly subjected to high speeds and temperatures.

If you are looking for TiAlN coated end mills for your shop, Online Carbide has plenty of options for you. They are an American tool manufacturer specializing in solid carbide end mills and drill bits. They offer tools with polished carbide finishes as well as options that are coated in TiAlN to help extend their working life.