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, silicon and molybdenum is applied at the following component ratio, wt %: titanium 93.1-95.0, silicon 1.0-1.4, molybdenum 4.0-5.5. Application of coating layers is performed with three cathodes located horizontally in one plane. First cathode is made of titanium and silicon alloy, second cathode is made of niobium and opposed to the first cathode, while the third cathode is made of titanium and molybdenum and positioned between the first and second cathodes. 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