Study of Properties of Nanostructured Multilayer Composite Coatings of Ti-TiN-(TiCrAl)N and Zr-ZrN-(ZrNbCrAl)N

Abstract

The structures of surface layers of the tool material, adapted to the conditions of the thermomechanical loading during the cutting process, can be formed with the use of different processing methods, the most effective of which is to deposit functional coatings on working surfaces of the cutting tool. During the studies, two nanostructured multilayer composite coatings (NMCCs) were considered: Ti-TiN-(TiCrAl)N and Zr-ZrN-(ZrNbCrAl)N. Metallographic studies were conducted, and the phase compositions of the coatings were determined by X-ray crystal analysis. The efficiency of tools made of carbide T14K8 with developed coatings was determined by comparative evaluation of tool life of a tool without coating, a tool with standard coating (TiN), and a tool with elaborated coatings (Ti-TiN-(TiCrAl)N and Zr-ZrN-(ZrNbCrAl)N) in turning structural steel 45. These tests allow noting the increase in tool life of a tool with elaborated NMCCs by up to 4 times as compared with tool life of an uncoated tool and by up to 2 times as compared with tool life of standard coating TiN. Meanwhile, NMCC of Ti-TiN-(TiCrAl) showed lifetime about 10% longer than NMCC of Zr-ZrN-(ZrNbCrAl)N). The longer lifetime of NMCC of Ti-TiN-(TiCrAl) conforms to its better adhesion characteristics and thinner nanosublayers of its wear-resistant layer.