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 chrome nitride is applied. Then the top layer of nitride of titanium, silicon and niobium is applied at the following ratio of components in wt %: titanium 88.6-93.0, silicon 1.0-1.4, niobium 6.0-10.0. Three cathodes arranged horizontally in one plane apply the coating layers. First cathode is made of titanium and silicon alloy, second cathode is made of chrome and opposed to the first cathode, while third cathode is composed of titanium and niobium 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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