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Currently, enterprises appoint cutting conditions according to reference data or on the recommendations of manufacturers. Often this information does not provide rational processing conditions. The situation is getting worse if we talk about modern automated metalworking equipment. The tool's premature failure involves high economic losses due to damage to the processed detail surface and according to receiving a manufacturing defect. Prevention of premature exit of metalworking tools will allow investigating changes of their operability under the effect of temperatures arising during cutting. Research subject: interchangeable cutter elements (plates) The goal of research: determine rational machining conditions based on electromagnetic properties of instrumental materials.The article analysed existing methods for determining the temperatures of the ultimate operational capability of cutting elements from tool hard alloys (THA). We analysed the existing test facilities. As a result, a new facility was developed to determine the temperature of the ultimate operational capability of cutting THA elements, eliminating existing devices' identified shortcomings. A description of the developed method of determining the temperature of ultimate operational capability by changing the electrical conductivity of cutting elements from instrumental two-carbide titanium-tungsten-cobalt hard alloys WC-TiC-Co is given. As a result of the work, electrical conductivity was studied depending on alloys' test temperature of group WC-TiC-Co. We determined the temperature conditions of ultimate operational capability of alloys 15%TIC+79%WC+6%CO, 5%TIC+75%WC+10%CO and obtained the corresponding temperature range of ultimate operational capability based on the obtained data. The obtained results can be used to determine rational cutting conditions when processing with these tool materials.

Currently increasing the cutting tools durability is an urgent problem. The high cutting conditions required to improve processing performance place special demands on tool materials. During the cutting process the tool working surfaces are subjected to intense exposure to high contact pressures and temperatures. Interaction with the processed material leads to an intensification of the adhesion, diffusion, and oxidation processes. All this causes rapid wear of the cutting tool. To reduce wear and prevent destruction the tool material must have high hardness, heat resistance, wear resistance, and strength. Hard and super-hard materials are used as tool materials for high-speed cutting, but their production is very expensive. Therefore it is more appropriate to apply coatings on the tool working surfaces in order to form the required properties. The article substantiates the need for the use of wear-resistant coatings on the working surfaces of cutting tools made of tool steels. A number of promising trends in the development of protective coating application technologies for cutting tools have been considered in the review.

Приведено аналитическое решение об условиях уменьшения технологической себестоимости обработки и возможности реализации высокоскоростного резания. Показано, что скорость резания ограничена экстремумом (минимумом) себестоимости обработки. Увеличить скорость резания и реализовать условия высокоскоростной обработки можно за счет повышения стойкости режущего инструмента путем применения более прочных и износостойких инструментальных материалов и покрытий инструментов, характеризующихся низким коэффициентом трения. An analytical solution is given on the conditions for reducing the technological cost of processing and the possibility of implementing high-speed cutting. It is shown that the cutting speed is limited by the extremum (minimum) of the cost of processing. It is possible to increase the cutting speed and implement high-speed machining conditions by increasing the tool life by using stronger and more wear-resistant tool materials and tool coatings characterized by a low coefficient of friction.

Studying methods for producing new composite materials based on compounds of the B-N-Al-Ti system using high pressure (up to 5 GPa) and temperatures (up to 1800 K), studying their physical characteristics to create tool materials based on them. Studying the prospects for the further development of research and the practical use of the results.

Although many studies have focused on the cutting performance of ceramic blades in processing different materials, few have reported on their application in wood processing. Thus, it is necessary to explore the cutting performance of ceramic tools in solid wood machining. The aims of this paper were to evaluate the cutting performance of Al2O3 and Si3N4 ceramic tools in the process of machining Manchurian ash (Fraxinus mandshurica Rupr.) and Chinese fir (Cunninghamia lanceolata) by means of analysing cutting force and surface roughness and to provide guidelines for factories for applying ceramic tools in the manufacture of solid wood furniture. Up-milling tests were conducted for each combination of cutting speed, tool material, and workpiece material, and each combination was replicated five times. Results showed that (1) cutting force and surface roughness decreased with increase of cutting speed and (2) cutting force and surface roughness resulting from using Al2O3 ceramic cutting tools were larger than those of Si3N4 ceramic cutting tools, especially when cutting Manchurian ash with its extractives. Overall, ceramic tools can be used in high-speed cutting of solid wood. Compared with Al2O3 ceramic cutting tools, Si3N4 ceramic cutting tools are more suitable for cutting solid wood, especially those with extractives. Si3N4 ceramic tools provided not only chemical stability, but improved final product quality. Validerad;2021;Nivå 2;2021-05-03 (johcin)

Electroplating onto polymeric materials is required for different purposes in various applications. Commercial polyurethanes (PU) are electrically insulator materials and durable at high temperatures. Nevertheless, the PU used in this study has a relatively higher electrical conductivity, lower thermal expansion and is a high density foam. In this work, surface metallisation of PU foam was studied to prepare the surface for subsequent electroplating processes. Surface metallisation was carried out by sensitisation, activation and electroless nickel (Ni) plating. Metallised surfaces were characterised according to surface morphologies after electrochemical Ni plating at different current densities and surface preparations. Roughness as well as electrical conductivity of the coatings was investigated. The results show that increasing current density adversely affects the surface morphology and metallisation processes enhance the surface conductivity of the foam.

The U.S. FDA Food Safety Modernization Act Preventive Controls for Human Food Rule underlines the importance of an effective environmental monitoring (EM) program. EM is used to determine harborage sites of microorganisms on processing equipment, assess effectiveness of sanitation programs, and prevent transmission of foodborne pathogens. This study characterizes commercially-available polyurethane foam (PUF) and cellulose (CELL) EM tools for their efficacy in the release of foodborne pathogens from their sponge matrices. Specifically, the objectives of this study were to 1) compare the ability of EM tools to release microorganisms into a recovery eluent, 2) characterize EM tool performance at decreasing inoculum concentrations, and 3) assess the impact of various operators during the processing of EM samples. Two bacteria (Listeria monocytogenes, Salmonella Typhimurium) and one human norovirus surrogate (Tulane virus [TV]) were compared at decreasing inoculum levels utilizing two elution techniques (mechanical stomacher, manually by operator), and across six operators. Data indicated that EM tool material composition impacted the release of microorganisms (p = 0.0001), where the PUF EM tool released TV more readily than the CELL EM tool. Conversely, the decreasing inoculum levels did not statistically differ in the release of microorganisms from the EM tool matrices. In addition, no significant difference was found between the machine stomacher and manual elution by human operator or between operators. Overall, the study provides a detailed characterization of two commercially-available EM tools, and the differences identified in this study can be used to improve the effectiveness of EM programs.

There are various methods for producing ceramic materials of enhanced strength properties in view of their application as tool materials: development of new compositions with set properties and new technologies for obtaining them; control of the sintering process and the ceramics microstructure by using some additives. The paper considers the results from a study of the tool life of experimental alumina-based ceramic cutting tools where unstabilized zirconia in quantities from 5 vol. % to 15 vol. % has been used as an additive. In addition, theoretical and experimental models have been developed. They reflect the complex influence of the cutting mode during turning (cutting speed and feed rate) and the percentage of the zirconia additive on the life of tools with square and triangular zirconia-toughened alumina ceramic inserts. By applying single-purpose optimization and a genetic algorithm, the optimal values of the following are defined: cutting speed $Vc$ ; feed rate $f$ and percentage of zirconia additive ( $A$ ), where the durability of the cutting tools is maximal - $Vc=200 \mathrm{m}/\text{min}, f=0.18 \text{mm}/\text{rev}, A=15\%$ .

The article is devoted to 3D modeling of the stress-strain state of the soldering zone of tool material in the burnishing body. For the first time, a wide range of tool materials is used for research, which can be used for the practical implementation of the burnishing processes of various groups of materials. The use of a thin-walled nanocoating by the CVD method is proposed for brazing diamond tools.

Friction Stir Welding (FSW) is a solid-state joining process for welding similar and dissimilar materials with restriction to its use in some low melting point material. Electric Resistance Friction Stir Welding (ERFSW) is a new solid-state joining method for joining high strength materials. The paper presents the fundamental principle of ERFSW processes, impact of the variable parameters on weld quality, basic tool design along with its utilization, tool material and process parameters. The zones of the joint created by heating effect have also been discussed with its micro-structural study in brief. It has been demonstrated that ERFSW of high strength alloy is an emerging technology with numerous commercial applications which may have its great utilization in the field of space and an ignition prone area like mine.

The development and application of high-speed cutting technology mainly depend on the progress of machine tool and tool technology, in which tool material plays a decisive role. High speed cutting requires the tool material to have good high temperature mechanical properties, high heat resistance, thermal shock resistance and high reliability. Ceramic cutting tools have become an important type of cutting tools for high-speed cutting because of a series of excellent characteristics such as high hardness, corrosion resistance, oxidation resistance and high temperature resistance. In this paper, the characteristics of cutting tools for high speed cutting and high speed cutting are briefly introduced, the research progress of ceramic cutting tools at home and abroad is summarized and analyzed, and a series of research hotspots at home and abroad, such as performance prediction and design theory of composite ceramic cutting tools used for high speed cutting, are emphasized. Finally, the research hotspots and development trend of composite ceramic cutting tools are summarized and explained.

Based on the idea of functionally graded material (FGM) and micro-nano-composite material (MNCM), the macro–micro design model of the Sialon/Si3N4 graded micro-nano-composite ceramic tool material was constructed by the combination of the thermal stress relief and surface compressive stress of the FGMs and the strengthening and toughening mechanisms of the MNCMs. The preparation process of the graded ceramic tool material and its cutting performance at high speed machining of Inconel 718 were investigated. The results indicated that the graded tool expressed high cutting performance, and had a self-sharpening characteristic under suitable cutting conditions, caused by the optimum mechanical properties and microstructure.

Over the years, machining industries are continuously striving to manufacture the parts at reduced cost and improved quality. This can be achieved by selecting appropriate set of tool–work materials and effective modelling and optimization of the process. Optimized grades of high-speed steel (HSS) are used to be treated as ultimate tool material till the 1930s [1]. However, American metalworking industry had shown three-time improvement in productivity with the use of same machines and manpower during the period 1939–1945.

The recent times have seen an expanding enthusiasm for the novel uses of electrical discharge machining (EDM) method, with specific accentuation on the capability of this procedure for surface modification. Other than the disintegration of work material amid machining, the inborn idea of the procedure results in the expulsion of tool material too. Through either dispersing metallic powders in the dielectric or by utilizing composite or both intentional material exchanges might be done under explicit machining conditions. In this review paper, secondary use of EDM is discussed which has revolutionized the concept of surface modification. A review of the wonder of surface adjustment by EDM and future potential applications has been presented in this paper.

Choosing the proper tooling materials is fundamental to all molding. Too stringent of requirements is just as detrimental as underestimating the need for suitable material properties.

Востребованность специализированных коррозионно-стойких сталей возрастает. Это связано с их уникальными эксплуатационными свойствами. В силу физико-механических характеристик этих сталей сложна их токарная обработка. Необходимо разработать рекомендации по обработке таких сталей применительно к современному высокопроизводительному станочному оборудованию. В работе приведены результаты проектирования новых инструментальных материалов для обработки этих сталей. Результаты позволили увеличить ресурс инструмента до 3 раз. Это выполнено при комплексном использовании экспериментальных данных и компьютерного имитационного моделирования в программной среде Deform. Выявлены критерии, при помощи которых моделирование осуществимо на требуемом уровне: износ инструмента, температура в зоне резания, напряжения в инструментальном материале и деформация инструментального материала., Demand for specialized corrosion resistant stainless steels is increasing. This is due to their unique performance properties. Due to the physical and mechanical characteristics of these steels, their turning is difficult. It is necessary to develop recommendations for processing such steels in relation to modern high-performance machine tools. The paper presents the results of designing new tool materials for processing these steels. The results allowed to increase the tool resource up to 3 times. This was done using complex experimental data and computer simulation in the Deform software environment. The criteria by which modeling is feasible at a sufficient level are identified. These are “tool wear”, “temperature in the cutting zone”, “stresses in the tool material” and “tool material deformation”.

Abrasive water jet machining (AWJM) is a non-traditional technology widely used in industries for processing of materials. AWJM is a replacement for the other modern and conventional machining processes that have thermal or mechanical disadvantages for workpiece and tool material. AWJM is mainly used for cutting but few researchers successfully used AWJM process for controlled depth milling, drilling, turning, peening etc. Today’s modern technology developed the AWJM process into a complete machining process that can produce precise and consistent results. AWJM can easily be employed for processing of intricate shape components made of brittle, hard, soft as well as ductile materials. A wide variety of materials ranging from stone, glass, titanium, steel, ceramics, composites, etc. can be easily machined by the AWJM.

Tool wear and life of cutting tools are significant evaluation criteria of machining processes. However, the occurring wear mechanisms are influenced by a number of factors such as the process parameters, tool geometry and the material properties of the tool and workpiece. Previous research has shown a high potential for the use of adapted cutting edge microgeometries on cemented carbide cutting tools. The optimal cutting edge rounding is strongly dependent on the tool material properties. However, the influence and relation between the properties of the cemented carbide tool, the microgeometry and the resulting tool wear are not yet completely understood. In this study the tool wear is investigated by systematically varying the mechanical and thermophysical properties of the tool material, the tool microgeometry and cutting process parameters. Significant influencing variables of tool wear are identified and existing relationships quantified. Results show that the occurring wear mechanisms depend on the cutting edge microgeometry as well as the mechanical properties of the cemented carbide. During continuous machining the minimum required cutting edge rounding is a function of the cemented carbide’s fracture toughness. This knowledge allows an adaption of the cutting edge microgeometry depending on the substrate properties to reduce the tool wear and achieve a longer tool life.

In manufacturing industries, high-speed machining of aluminum alloys is highly recommended for achieving better productivity in terms of cutting force reduction and improved surface finish. Even though an overwhelming number of process parameters affect the high-speed machining operations, tool material is considered to be the most predominant factor in determining the machining performance. Hence, in the present work, experimental and simulation analyses are carried out for understanding the effect of different tool materials in high-speed machining of aluminum alloy. Formation of dead metal zone is taken as the fundamental criterion for analyzing the discrepancy in cutting forces, and the same is discussed in detail in the present paper.

In this paper some results concerning the cutting temperature and surface roughness using different milling conditions (tool material, cutting speed, speed feed and depth of cut) are presented.

The paper explores the performance of alumina- based ceramic cutting tools, rated with the tool life, surface roughness and cutting power used as evaluation parameters when turning C45, 42Cr4 and 100Cr6 steels. Adequate theoretical-experimental models have been built. The performance between mixed alumina ceramic tools and zirconia toughened alumina ceramic tools is compared and appropriate combinations of processed and tool material are recommended. It was found that in the whole study ranges of cutting speed and feed for all machined materials, the cutting tools of mixed ceramic show better performance evaluated with the surface roughness parameter. In the area of high cutting speeds and large feeds, cutting tools of mixed ceramic show better tool life and cutting power.

Tool materials used for polymeric composite blank machining, kinds of tool material wear arising at machining these blanks, and also the impact of technological parameters upon tool wear are considered. The obtained results allow estimating the potentialities of physical models at polymeric composite blanks cutting.

The work is aimed at selecting a promising grade of a tool material, whose physical-mechanical characteristics would allow using it for processing the surfaces of discontinuous parts in the presence of shock loads. An analysis of the physical-mechanical characteristics of most common tool materials is performed and the data on a possible provision of the metal-working processes with promising composite grades are presented.

One kind of TiB2/TiC composite ceramic tool material toughened by graphene nanosheets was fabricated by spark plasma sintering. Effects of graphene nanosheets on microstructure, mechanical properties and toughening mechanisms were investigated. The results indicated that TiB2/TiC with 0.1 wt% graphene nanosheets sintered at 1800 °C with the holding time of 5 min obtained full densification and optimal mechanical properties. Its fracture toughness and Vickers hardness were 7.9 ± 1.2 MPa m1/2 and 20.0 ± 0.7 GPa, respectively. Excess graphene nanosheets had no effects to toughness improvement. Fracture toughness was increased by 31.7% in comparison with the TiB2/TiC without graphene nanosheets. Toughness enhancement mainly benefited from crack bridging, also slip-stick effect of graphene made it hard to detach and effectively restrained crack extension.

A Si3N4/(W, Ti)C graded nano-composite ceramic tool material was developed and its high temperature flexural strength and fracture toughness were studied. With increased testing temperature, the flexural strength demonstrates a tendency to first decrease gradually and then decrease sharply, and the transition temperature is 1000 °C. The softening effect of glassy phases, the oxidation effect and the surface cracks result in the gradual decrease of flexural strength while the growth and merge of microcracks and cavities results in the sharp decrease. The fracture toughness under elevated temperatures increases gradually and then decreases dramatically, and the transition temperature is 1000 °C as well. The plastic deformation behavior, microcrack toughening effect and the healing effect of SiO2 layer result in the gradual increase of fracture toughness while liquefaction of the grain-boundary phase results in the sharp decrease. Due to reasonable composition distribution and induced compressive residual stress in the surface layers, the graded material shows a significantly better high temperature properties than the homogenous one.

There are several testing methodologies to characterize the friction and wear behavior of coated or special heat treated dies and forging materials for closed-die forgings. In order to measure the friction coefficient, the wear rate, galling or fretting behavior or the effect of lubricants, three different testing types (ring compression testing, a self-made high temperature rotation tribometer and hot torsion friction) are described in detail. To meet the practical requirements, the influencing factors like temperature level, sliding speed, contact pressure and specific surface treatments or coatings have to be varied in proper ranges. The results may contribute to find better friction models for finite element analysis, and consequently to a better prediction of the material flow and other related parameters. By confocal microscopy and a full metallographic investigation, the microstructural changes near the interface are studied, which lead to a better understanding of the wear and degradation mechanisms involved. These findings may help to find out countermeasures for life time improvements of the forging dies.

Nanostructured multicomponent (TiAlSiY)N coatings were fabricated by the cathodic-arc physical vapor deposition (CA-PVD). In this study, a bias potential applied to the substrate was − 200 and − 500 V, and changes in structure and properties of coatings were investigated. Samples had a single-phase state with a face-centered cubic (FCC) lattice. Small crystallites of about 7.5 nm and texture with [110] axis were observed at − 500 V. However, lower bias potential resulted in the formation of crystallites of about 41.6 nm with [111] preferred orientation. Moreover, coatings were characterized by superhard state and demonstrated low wear, high abrasion and crack resistance. The testing of the polycrystalline cubic boron nitride (PCBN) cutting inserts covered with (TiAlSiY)N revealed an increase in the tool life coefficient during cutting by 1.66 times in comparison with the base tool material. Therefore, (TiAlSiY)N coating is a perspective material for application as a protective layer in cutting tools.

In the present study, cutting conditions in face milling of AISI H13 hardened steel were optimized considering the performance of cemented carbide tool material. The initial microscopic mechanical property of the cemented carbide tool material was analyzed based on damage mechanics and boundary element method. Taking the initial microscopic mechanical property of the tool material, the initial macroscopic mechanical property of the tool material and external loads in the cutting process into account, a new tool life indicator was proposed. On the basis of the characteristics of tool life indicator and specific cutting energy, a theoretical method was established for the optimization of cutting conditions. The optimum cutting conditions were distinguished for different milling conditions. Feed per tooth fz with a value around 0.2 mm/tooth and cutting speed v ranging from 150 to 250 m/min should be used in symmetric milling to acquire a relatively long tool life and relatively low energy consumption. In down milling, feed per tooth fz should be in the range of 0.15 to 0.2 mm/tooth and cutting speed v should be between 100 and 200 m/min. Feed per tooth fz close to 0.2 mm/tooth and cutting speed v between 200 and 300 m/min should be adopted in up milling.

Ever since the invention of plastics, packaging has become extremely cheap and efficient. In recent times, the demand for more ecological packaging is increasing leading back to the roots of using naturally available resources, which are biodegradable. The manufacturing process of the Green Fiber Bottle (GFB) is based on moulding of wood fibers. The process is still at the research stage and not commercialized. Tooling is the most critical element in moulding and should be adapted to quick water removal techniques, such as Impulse Drying Technology. In this work, functional requirements for the development of a robust tooling solution are identified. Tooling alternatives are investigated and compared with the capacity to enable water removal. Characterization and assessment of porous tool materials using computed tomography are also outlined and discussed.

This work was funded by the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement n° 283871 and the Swiss National Science Foundation (SNSF, Project 310030_143359 to KZ). Chimpanzees’ natural propensity to explore and play with objects is likely to be an important precursor of tool use. Manipulating objects provides individuals with pivotal perceptual-motor experience when interacting with the material world, which may then pave the way for subsequent tool use. In this study, we were interested in the influence of social models on the developmental patterns of object manipulation in young chimpanzees (Pan troglodytes schweinfurthii) of the Sonso community of Budongo Forest, Uganda. This community is interesting because of its limited tool repertoire, with no records of stick-based foraging in over 20 years of continuous observations. Using cross-sectional data, we found evidence for social learning in that young individuals preferentially played with and explored materials manipulated by their mothers. We also found that object manipulation rates decreased with age, whereas the goal-directedness of these manipulations increased. Specifically, stick manipulations gradually decreased with age, which culminated in complete disregard of sticks around the age of 10 years, a pattern not found for other tool materials, which were all used throughout adulthood. Overall, young chimpanzees initially explored and played unselectively with any object found in the environment before becoming increasingly influenced by their mothers’ goal directed object manipulations. Postprint

WC-Co cemented carbide has been extensively used as a tool material for a long time. It is a very old but still widely used material because of high hardness, strength, and wear resisting properties. The present study deals with critical characterization of wear in WC-Co tip of the coal mining tools (radial picks). These picks were used for excavating coal from an underground mine. Mainly four different types of wear mechanisms have been characterized. The most probable causes behind each wear phenomenon have been explained comprehensively.

The main purpose of the study is to test the applicability of different cutting tools in producing tool-making equipment and to lay emphasis on the mechanisms present in the high-speed-cutting. The study would be of great benefit in the design and the selection of tool materials and also to control tool wear. The machining on EN36 steel was performed on CNC Turning Machine and design of experiments were made by using Taguchi method. The tool flank wear patterns were observed by tool maker’s microscope and comparative study is made for both coated and uncoated tools inserts. The comparison performed identifies the best validated cutting tool having improved performance among coated and uncoated inserts and gives optimum parameters in order to reduce the cutting forces for all cutting speeds. These values obtained shows coated tool inserts outperformed over uncoated at higher cutting speeds.

The research results on the wear of cutting tools made by sintering high-speed steel powders have been presented. It has been shown that powder tool materials based on high-speed steel additionally alloyed with titanium carbide have high wear resistance and can be classified as a new class of self-organized tool materials. As has been shown by the research, the wear resistance of these tools is 2–3.5 times higher than the wear resistance of standard high-speed steel tools.

Medical screws are a common mass-produced implantable medical component made of Titanium. To machine the threads of these types of components, thread whirling with carbide tools is typically used. However, tool wear and low cutting speed limit the productivity and increase the manufacturing cost of such medical parts. In this study, a direct motor driven thread whirling unit for an advanced Swiss-type CNC lathe was developed and it was used with advanced tool materials such as low binder content Cubic boron nitride (CBN) and Polycrystalline diamond (PCD) to find a cost-effective and more productive alternative to carbide tools.

ZrB2/SiC/WC ceramic tool materials with a WC content of up to 10 vol% were prepared using spark plasma sintering technology. The mechanical properties at room temperature showed that the ZrB2/SiC/WC ceramic tool material with a WC content of 5 vol% had the best comprehensive mechanical properties, with a hardness, flexural strength, and fracture toughness of 19.1 GPa, 590 MPa, and 4.9 MPa·m1/2, respectively. With the increase in temperature, the hardness and fracture toughness of the ZrB2/SiC/WC ceramic tool materials gradually decreased; however, the flexural strength first increased and then decreased. When the temperature was 600 °C, the flexural strength reached a maximum value of 630 GPa, which was an increase of 6.8% when compared to that at room temperature. The increase in flexural strength was mainly due to the increase in the transgranular fracturing during the fracture process of the ZrB2/SiC/WC ceramic tool material. Dry machining tests of 40Cr hardened steel were performed using ZrB2/SiC/WC ceramic tools. As the cutting speed increased, the tool life gradually decreased, but the surface quality of the workpiece gradually increased. When the cutting speed was 300 m/min, the tool life of the ZrB2/SiC/WC ceramic tool was 15.8 min, and the surface roughness Ra of the workpiece after cutting was between 1.0 and 2.0 μm. According to the wear morphology, adhesive wear was the main form of the ZrB2/SiC/WC ceramic tools.

Ceramic cutting tools are mainly used in high-speed dry machining, thus the tool material is in high temperature friction state with the workpiece material during cutting. The tribological characterizations have a direct impact on the cutting performance of the tool. Therefore, tribological characterizations of two kinds of ceramic tool materials with different mechanical properties against hardened steel H13 were compared at the same temperature, one material is Al2O3/(W,Ti)C/Ni with Ni (marked as AWTN), another is Al2O3/(W,Ti)C without Ni (marked as AWT). Also, the variation of tribological characterizations of AWT ceramic tool material with different temperatures was emphatically investigated. The results showed that the average friction coefficients of AWT and AWTN decreased with the increase of sliding speed under the same load, and the friction coefficient of AWT was lower than that of AWTN. Although AWTN material had better flexural strength and fracture toughness than AWT at ambient temperature, yet better hardness of AWT material both at room temperature and high temperature led to the lower friction coefficient and lower wear rate, indicating that the hardness had a greater impact on the wear of ceramic tool materials. The friction coefficient of AWT decreased with the increase of load and increased with the increase of temperature. The wear mechanism of Al2O3/(W,Ti)C ceramic tool material was different at different temperatures. The conclusion of this research had important guiding significance for the selection of cutting tools and cutting parameters in order to improve the machining quality.

Effects of HfC addition on microstructures and mechanical properties of TiC 0.7 N 0.3 -based and TiC 0.5 N 0.5 -based ceramic tool materials were investigated. The results showed that the same by-products such as HfN 0.4 , HfNi, Ti 0.76 Hf 0.24 Ni, TiNi 0.85 Co 0.15 and HfCo 6 were discovered in these ceramics. To some extent, HfC additive can inhibit their denitrification in the sintering process. The HfC particles can produce the crack flection and a suitable HfC content can improve mechanical properties of these ceramics effectively. Besides, the TiC 0.5 N 0.5 -HfC ceramics exhibited a poor sinterability compared to TiC 0.7 N 0.3 -HfC ceramics, showing much more pores in fracture and polished surfaces micrographs; grains in TiC 0.7 N 0.3 -HfC ceramics are finer than that in TiC 0.5 N 0.5 -HfC ceramics; the HfC particles dispersion in TiC 0.7 N 0.3 -HfC ceramics is more uniform than that in TiC 0.5 N 0.5 -HfC ceramics; thus, the mechanical properties of TiC 0.7 N 0.3 -HfC ceramics are superior to that of TiC 0.5 N 0.5 -HfC ceramics. In addition, their fracture mechanism is a combination of transgranular fracture and intergranular fracture. As a consequence, the enhancement of their mechanical properties is conducive to the presence of intermetallic compounds, the fine microstructure and the suitable HfC content.

Reforming obsolete technologies, increasing production of new machines and devices are impossible without modern and reliable instrumentation. The high structural complexity of the manufactured parts creates problems for the use of a blade tool that, along with high hardness, has considerable brittleness. As a rule, the processing of intermittent surfaces by turning is accompanied by chipping of the cutting edges.The disadvantages of alternative grinding technologies are the high cost of equipment, low productivity, as well as the problems of forming the required quality parameters of the surface layer due to the specificity of operation of the grinding tool.The solutions protected by patents of the Russian Federation, allowing to exclude negative factors of intermitted cutting are offered. The scientific novelty of the decisions made is to give the damping tool a special position that excludes negative interaction between sharp tip of cutting element and intermittent surface, which provides the possibility of stable operation of brittle tool material on the basis of the developed mechanism for controlling the position of the cutter tip.

Cutting experiments of sintered steel Fe–2Cu–0.8C under different lubrication/cooling conditions and with different tool materials were performed in order to clarify the reasons for the low machina...

The reinforcing effect of multi-layer graphene (MLG) on the fracture toughness and flexural strength of an Al 2 O 3 /TiC ceramic tool material was studied by theoretical analyses and experimental observations. The crack paths induced by Vickers indentation were analyzed using the fractal method to distinguish the possible reinforcing mechanisms. High-level reinforcement was observed in the Al 2 O 3 /TiC ceramic with well-dispersed MLG. The average indentation fracture toughness was 6.14 MPa m 1/2 , against 4.98 MPa m 1/2 for the Al 2 O 3 /TiC ceramic, and the flexural strength improved from 749.6 MPa to 981.5 MPa for the 0.2 wt%-added MLG. The main reinforcing mechanisms are proposed to be the hindering effect of MLG on the crack path and the synergistic effect of weak and strong bonding interfaces, as well as grain refinement.