NEW MULTILAYER PVD-COATING TECHNIQUE FOR CUTTING TOOLS

The production process and the properties of TiAlN(x)-based hard multilayer coatings for cutting tools will be described. Twist drills and hobs were coated with this new hard multilayer coating to demonstrate the performance on tools. Functional, stress-relieved TiAlN(x) coatings with a low coefficient of friction and good adhesion were obtained using an enhanced plasma for both the ion etching and the sputter ion plating coating procedures. The plasma assistance was provided by the use of the plasma booster technique. With this technique, ion current densities of several milliamps per square centimetres were achieved at the substrates. The coated twist drills were tested in cutting experiments. The microhardness of the coatings was evaluated up to a temperature of 600-degrees-C to outline the effects of the superior cutting results under heavy machining conditions.