A.S. Vereschaka

Improving the Efficiency of the Cutting Tools Made of Mixed Ceramics by Applying Modifying Nanoscale Multilayered Coatings

The paper studies the influence of properties of a tool made of mixed ceramic by applying modifying with nanoscale multi-layered coatings on machinability of hardened tool steel XVG. The paper also examines the influence of cutting speed on wear resistance of mixed ceramic with nanoscale multilayered coatings. The mathematical models that found out the dependence of tool life of a ceramic tool with coating from cutting speed were developed.

Development of Technological Means for Formation of Multilayer Composite Coatings, Providing Increased Resistance of Carbide Tools, for Different Machining Conditions

The present work documents the results of development a methodological and technological means for the formation of multilayer composite coatings essential to increasing the tool life of a cemented carbide cutting tool edge. A methodology, based on of a rational choice of structure, architecture, and properties of a multilayer coating for tool edge working in various cutting conditions, is formulated. The results demonstrate an increase of efficiency of the carbide tool edge life based on the methodology stated above, and are presented here.

Nano-Scale Multi-Layered Coatings for Cutting Tools Generated Using Assisted Filtered Cathodic-Vacuum-Arc Deposition (AFCVAD)

The subject of this study were nano-nanoscale multilayer coatings formed using the process of filtered cathodic vacuum arc deposition in assisting high-energy ions of chromium. We used a special emitter (implantor) to generate chromium ions with high energy. Such key parameters of coatings as composition, structure, a thickness, hardness, adhesion in relation to a substrate obtained at various energy of chrome ions have been studied. It is establish the positive change of key properties of coating deposited on carbide inserts WC/CrC/Co, WC / (Co-Re), TiC/TaC/Co at assisted impact of ions Cr at ion acceleration voltage within the range of 10-40 kV. The results of measurement of parameters of coatings with use nanoindentometer are consistent with the X-ray analysis of the stresses in the coating (XSA study). The mechanisms of the effect of modified properties of coatings formed in assisting the filtered cathodic vacuum arc deposition on the properties of the carbide inserts in cutting structural steels and hard-to-cut nickel alloys have confirmed the high efficiency of the deposition process developed coatings and coating compositions.

Improvement of structure and quality of nanoscale multilayered composite coatings, deposited by filtered cathodic vacuum arc deposition method

This article studies the specific features of cathode vacuum arc deposition of coatings used in the production of cutting tools. The detailed analysis of the major drawbacks of arc-Physical Vapour Deposition (PVD) methods has contributed to the development of the processes of filtered cathodic vacuum arc deposition to form nanoscale multilayered composite coatings of increased efficiency. This is achieved through the formation of nanostructure, increase in strength of adhesion of coating to substrate up to 20%, and reduction of such dangerous coating surface defects as macro- and microdroplets up to 80%. This article presents the results of the studies of various properties of developed nanoscale multilayered composite coating. The certification tests of carbide tool equipped with cutting inserts with developed nanoscale multilayered composite coating compositions in longitudinal turning (continuous cutting) and end symmetric milling, and intermittent cutting of steel C45 and hard-to-cut nickel alloy of NiCr20TiAl showed advantages of tool with nanoscale multilayered composite coating as compared to the tool without coating. The lifetime of the carbide inserts with developed NMCC based on the system of Ti–TiN–(NbZrTiCr)N (filtered cathodic vacuum arc deposition) was increased up to 5–6 times in comparison with the control tools without coatings and up to 1.5–2.0 times in comparison with nanoscale multilayered composite coating based on the system of Ti–TiN–(NbZrTiCr)N (standard arc-PVD technology).

Carbide Tools with Nano-Dispersed Coating for High-Performance Cutting of Hard-to-Cut Materials

The problem of increasing performance of carbide too lin machining hard-to-machine materials has been studied. Composite material was developed comprising carbide with heat-resistant bond Co-Re, significantly increasing resistance of carbide to thermoplastic deformation, and nanodispersed multilayer composite coating, significantly reducing thermomechanical impact on cutting part of tool.Studies to find the performance of tool made of developed composite material in turning hardened steel40H and heat-resistant nickel alloy HN77TYUR have shown its superiority compared to commercial carbides with coatings of modern generation.Studies have found out practicability of using VRK-13 cobalt-rhenium carbides with reduced content of expensive rhenium from 9% (weight) Re to 6% (weight), and it is highly competitive by heat resistance with VRK-15 carbide and is significantly superior to it by its strength.Results of cutting properties research forultra-dispersed Re-added WC-Co-carbides with Ti-TiN-TiCrAlNnano-dispersed multilayer composite coating are presented at longitudinal turning of constructional steels and hard-to-machine alloys. It is shown that the combination of ultra-dispersedheat-resistant WC-(Co,Re)-carbides and wear-resistant Ti-TiN-TiCrAlN coatings increase cutting properties of tool in some times.

Development and Research of Nanostructured Multi-Layered Composite Coatings for Tool Made of Tungsten-Free Carbides (Cermets)

This paper discusses the issues of improving the efficiency of cutting tool made of tungsten-free carbides (cermets) by using nanodispersed multi-layered composite coatings formed by use of innovative processes of filtered cathodic vacuum arc deposition (FCVAD). The paper presents the concept of architecture of nanostructured multi-layered composite coatings, methodology for choice of function and rational component parameters of architecture for tools made of cermets. Developed compositions of nanostructured multi-layered composite coatings contributes to significant improvement of properties of cutting tool made of cermets in cutting constructional steel and expansion of their application area for machining of heat-resistant alloys.

Cemented Carbides for Machining of Heat-Resistant Materials

The optimum ratio of rhenium and cobalt in Co-Re binder of a cemented carbides based on the analysis of phase diagrams and studying the carbides properties is defined.It is shown that properties of carbide binder at the same ratio of rhenium and cobalt are also the same, and the carbide properties are determined by the amount of carbide binders.Researches of wear resistance of the tool from carbides with Co-Re binder at machining of a constructional steel and hard-to-machining alloys have confirmed their high efficiency.

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.

Development of modifying compounds for multilayer nanostructured coatings for cutting tools

The subject of this study was to research and develop modified multilayer nanostructured wear-resistant coatings (NWC) for cutting tools. NWC are formed through the innovation process of filtered cathodic vacuum-arc deposition (FCVAD). The processes of FCVAD allow forming NWCs by filtering vapour-ion flow of macro/micro particles in the plasma torch of vacuum arc, using the plasma duct of special structure isolated from the station chamber, when the angle of rotation of the plasma stream is 120°. This work presents the configuration of the system, alongside the influence of process parameters on the output. The topology of the coatings is presented together with the hardness and a comparison between standard physical vapour deposition (arcPVD) and FCVAD coating technologies. Machining tests were undertaken in turning of standard HB200 steel and heat resistant nickel alloy. The results are presented in terms of tool flank wear. It is shown that the application of the NWC secured 2-6 fold extended tool life.