Mechanical properties and cutting performance of nanocomposite Cr–Si–N coated tool for green machining

In this paper, comparative studies on mechanical properties and cutting performance between CrN and Cr–Si–N coatings for green micro end-milling were conducted. Ternary Cr–Si–N coatings, in which Si was incorporated into CrN, were synthesized onto WC–Co substrates using a hybrid system of arc ion plating and sputtering techniques. The high hardness of Cr–Si–N coatings was related to the composite microstructure consisting of the fine CrN crystallites and amorphous Si3N4. The average friction coefficient of Cr–Si–N coatings gradually decreased with increase of Si content in CrN coatings. Cutting tests were carried out to evaluate the characteristics of micro cutting in vertical machining center using ultra-high speed air turbine spindle. An integrated evaluation system of cutting tools was introduced. Consequently, the Cr–Si(9.3 at.%)–N coated end-mill using semi-dry machining showed good cutting performance under ultra-high speed cutting condition.