Gaik V. Oganyan

Study of Mechanism of Failure and Wear of Multi-Layered Composite Nano-Structured Coating Based on System Ti-TiN-(ZrNbTi)N Deposited on Carbide Substrates

The aim of this paper is to study physical and chemical properties of nanostructured multi-layered composite coating based on three-layered architecture of Ti-TiN-(ZrNbTi)N, deposited to a carbide substrate, as well as to study the mechanism of wear and failure of carbide tools with coatings under the conditions of stationary cutting. The coating obtained by the method of filtered cathodic vacuum arc deposition (FCVAD). The microstructure of carbide cubstrate with coating on transverse cross-section were investigated, as well as its hardness, strength of the adhesive bond to the substrate, chemical composition and phase composition. The studies of cutting properties of the carbide inserts with developed coating was conducted on a lathe in longitudinal turning of steel C45 (HB 200). Analysis of mechanisms of coated tool wear and failure was carried out, as well as - the study of processes of diffusion and oxidation in the surface layers of the coated substrate.

Improving Efficiency of End Mills by Deposition of Modifying Nano-Scale Multilayer Composite Coatings

The study considers the challenge of improving the efficiency of end mills made of carbides through modification of physical and mechanical properties of tools by forming nanostructured multilayer composite coatings on its working surfaces with the use of filtered cathodic vacuum-arc deposition (FCVAD). The system and structure of three-component nanostructured multilayer composite modifying coatings for deposition on the working surfaces of the end mills are developed. The study presents the results of laboratory and industrial tests of end mills with coatings designed for conditions for rough and finish machining.

Improving the Efficiency of Carbide End Mills by Deposition of Nano-Scale Multi-Layered Composition Coatings

The study has considered the challenge of improving the efficiency of carbide end mills through modification of the physical and mechanical properties of tool by forming on its working surfaces nanostructured multi-layered composite coatings with use of filtered cathodic vacuum arc deposition (FCVAD). The technique of deposition of three-component multi-layered composite coatings with nanosized grain structure and thickness of sublayers on working surfaces of end mills has been developed. The developed coatings contain three key components, each of which has a strictly functional purpose specifying enhanced wear resistance, strong adhesive bonding with tool material and barrier properties with regard to heat flows and diffusion, and that allows improving the efficiency of carbide end mills. The study has found out that when carbide end mills with developed coatings are used at cutting, the cyclic thermomechanical stresses acting on the cutting part of the tool during the cutting stroke and idle run of cutting edge of end mills are smoothed, and that leads to the decrease in the rate of tool wear and improves the efficiency of carbide end mills. The study was supported by grant No. 9.251.2014/K, project code 251.

Wear Mechanism and Failure of Carbide Cutting Tools with Nanostructured Multilayered Composite Coatings

The aim of this work is to study physical and chemical properties of nanostructured multi-layered composite coating based on three-layered architecture, deposited to a carbide substrate, as well as to study the mechanism of wear and failure of coated carbide tools under the conditions of stationary cutting. The coating were obtained by the method of filtered cathodic vacuum arc deposition (FCVAD). Here, the microstructure of coating as well as its hardness, strength of the adhesive bond to the substrate, chemical composition and phase composition were investigated on a transverse cross-section of experimental samples. The studies of cutting properties of the carbide inserts with developed coatings was conducted on a lathe in longitudinal turning of steel C45 (HB 200). The analysis of mechanisms of wear and failure of coated tool was carried out, including the processes of diffusion and oxidation in the surface layers of the coated substrate. Tools with harder and less ductile coatings showed less steady kinetics of wear, characterized by sharp intensification of wear and failure in transition from “steady” to drastic wear, i.e., at the end of the tool life. The X-ray microanalysis showed a considerable increase in oxygen content in the transverse cracks in the coating.