Cutting tools made of layered composite ceramics with nano-scale multilayered coatings

摘要

The cutting tool material with an optimum combination of sufficient toughness and strength, high hardness, heat stability and wear resistance, low physical-chemical inertness in relation to a workpiece material is a good alternative to the standard tool materials used in heavy cutting conditions like: high-speed machining, dry cutting, cutting of hard-to-machining materials, etc. In the present paper the example of development of such a material in the form of layered composite material build up on a carbide substrate, a ceramic layer and a nano-scale multilayered coating is reviewed. Each element of a layered tool material fulfills individual functions. The carbide layer provides the raised toughness and strength of tool material, the ceramic layer provides resistance of a tool material to oxidation, corrosion and high-temperature weakening at elevated temperatures, the nano-scale multilayered coating decrease of thermal-mechanical stresses on the rake face of the tool and eliminates superficial defects of the ceramic.