SURFACE-COATED CUTTING TOOL

摘要

The object of the present invention is to provide a surface-coated cutting tool that offers superior lubricity and long tool life even when used under usage conditions such as mist cutting. In the surface-coated cutting tool of the present invention, a coating layer formed from an outermost layer and an inner layer disposed on a substrate surface. The inner layer is formed from a periodic table group IVa, Va, VIa metal, Al, Si, B compound. The outermost layer is formed from aluminum nitride or aluminum carbonitride. The outermost layer has a chlorine content of more than 0 and no more than 0.5 atomic percent. The protective coating on the tool surface is made easier to form during cutting by further adding a predetermined amount of chlorine to the film formed from aluminum nitride, which provides thermal stability and lubricity. Lubricity can be increased by using this protective coating.