METHOD OF PRODUCING SANDWICHED COATING FOR CUTTING TOOL Russian patent published in 2017 - IPC C23C14/06 C23C14/24 B23B27/14 

FIELD: metallurgy.

SUBSTANCE: sandwiched coating is applied by vacuum plasma method. First, a lower layer of niobium nitride is applied. Then, an upper layer of nitride of titanium, zirconium and aluminium is applied at the following component ratio, wt %: titanium 73.0-81.0, zirconium 12.0-16.0, aluminium 7.0-11.0. Application of coating layers is performed with three cathodes located horizontally in one plane. The first cathode consists of titanium and zirconium, the second one consists of niobium and is located opposite to the first one, and the third one consists of alloy of titanium and aluminium and is located between them. Bottom layer is applied with the help of second cathode while top layer is applied by first and third cathodes.

EFFECT: higher cutting efficiency.

1 tbl