The article presents the results of the study that describes how the wear-resistant duplex coatings fabrication on the surface of cutting tools influences the tool life. Wear-resistant duplex coatings were deposited in one fabrication cycle in the upgraded vacuum chamber NNV-6.6-I1 additionally equipped with the PINK plasma source for plasma-chemical treatment of the surface, ion modification and coating deposition, and with magnetic-arc filtration system that allows synthesizing a coating having almost no microdroplets. Here are the results of the study of vacuum ion-plasma multilayered TiAlCrN coatings fabricated during ion-assisted treatment of the surface and deposition of the coating and without diffusion charge created by the plasma generator, and during duplex treatment that includes initial ion modification of the surface layer. The impact of TiAlCrN duplex coating on the properties of cutting tools made of WK-6 hard alloy during machining of nickel alloys has been established. It has shown that TiAlCrN duplex coating fabricated by successive modification of the surface layer by reactive gas atoms (N2) and of the multilayered coating of three-component plasma generated by arc evaporators with Ti, Al, Cr cathodes in a continuous vacuum cycle and simultaneous plasma treatment considerably increases the hard cutting tool life.