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 zirconium nitride is applied. Then, an upper layer of nitride of titanium, aluminium and silicon is applied at the following component ratio, wt %: titanium 87.7-91.9, aluminium 7.0-11.0, silicon 1.1-1.3. Three cathodes arranged horizontally in one plane apply the layers. First cathode is made of titanium and aluminium alloy, second cathode is made of zirconium and opposed to the first cathode, while third cathode is made of titanium and silicon alloy 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.

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