This dark grayish color PVD coating is harder than TiN coating and can be used in high temperature environments and for improved lubricity.
Aluminum Titanium Nitride or Titanium Aluminum Nitride (TiAlN) is a thin film coating that was developed from Titanium Nitride. It is primarily used in high temperature environments above the limits of TiN usage. This coating works by forming a thin surface layer of Aluminum Oxide ceramic. As the layer wears in hot conditions it continuously reforms.
TiAlN is typically applied to cutting tools to improve tool life. This coating can extend tool life when compared to uncoated tooling. The thin coating is environmentally safe, and is applied using a physical vapor deposition vacuum system.
The advantage of using a coating with cutting tools usually has to do with heat displacement. The coating protects the tool from the high heat involved with most machining applications. Although rotary broaching is a relatively low heat operation, the hardness contributes to decreased downtime and longer tool life.
The TiAlN coating part number code for Polygon’s rotary broaches is the letter ‘D’. For example, if you would like to order a 1/4″ hex broach with 1/2″ shank and TiAlN coating, you would add the letter ‘D’ to the end of the part number H02525B. The new part number would be H02525BD.