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The aim of this work was to investigate mechanical and cutting properties, as well as the nature of wear and failure of carbide cutting tools with modifying coatings of two types: nano-structured multi-layered coating Zr-ZrN-(ZrCrAl)N, applied through the use of the technology of filtered cathodic vacuum arc deposition, and multi-layered nano-structured and gradient coating Ti-(TiAl)N-(TiAl)N, applied through the use of the technology of LARC ® (lateral rotating cathodes). It is found out that the both types of coatings under test significantly improve tool life of a carbide cutting tool. The studies of mechanisms of wear and failure of carbide tools with coatings under test, conducted at macro and micro levels, have identified their major differences and revealed their most preferable field of application. The carbide tools, equipped with cutting inserts with the nano-structured multi-layered coating under study, provided a significant increase in cutting properties (tool life) of the tool in comparison with the uncoated carbide tool and in comparison with the reference carbide tool with TiN coating. The tool with the coating Ti-(TiAl)N-(TiAl)N under study demonstrated the increased wear resistance during 30–35 min of cutting, and then, the process of coating failure and tool wear was sharply intensified. For the tool with coating Zr-ZrN-(ZrCrAl)N, the tests revealed more evenly balanced wear during the whole operating time between failures. It should be noted that NMCC Zr-ZrN-(ZrCrAl)N are substantially thinner, and that fact predetermines their better resistance to failure because of crack formation, and the technology of its generation is more cost-effective.

In this study, milling of the Inconel 718 superalloy was performed in dry conditions with the aim of reducing the adverse effects of the coolant on the environment. As is known, cutting tools quickly complete their life due to the high-temperature on the cutting zone in the dry condition milling process of hard materials. The nanocomposite TiAlSiN/TiSiN/TiAlN thin film was deposited on the cutting tools and then subjected to cryogenic heat treatment to increase the tool life of the used cutting tools. As a result, the life of the cutting tools has been increased by the thin film coating and cryogenic heat treatment applied to the cutting tools. After cryogenic treatment at a cutting speed of 30 m/min, the tool life of uncoated, TiN-, nanocomposite TiAlSiN/TiSiN/TiAlN-, and TiAlN-coated carbide cutting tools increases by 54, 110, 29, and 30%. The applied cryogenic heat treatment resulted in an 18% increase in the hard η phase of the structure of the carbide cutting tools. In addition, cryogenic heat treatment improved the adhesion of hard coatings to the substrate. The EDS analysis applied to the worn tools revealed that the mechanisms causing wear of the cutting tools were abrasion and adhesion.

Cryogenic technique is the use of a cryogenic medium as a coolant in machining operations. Commonly used cryogens are liquid nitrogen (LN2) and carbon dioxide (CO2) because of their low cost and non-harmful environmental impact. In this study, the effects of machining conditions and parameters on the wear mechanism were analysed in the milling process of AISI 4340 steel (32 HRC) under cryogenic conditions using a multilayer coated carbide cutting tool (TiAlN/AlCrN). A field emission scanning electron microscope with energy-dispersive X-ray analysis was used to examine the wear mechanisms comprehensively. At low machining parameters, abrasion and adhesion were the major wear mechanisms which occurred on the rake face. Machining at high machining parameters caused the removal of the coating material on the rake face due to the high temperature and cutting force generated during the cutting process. In addition, it was found that continuously adhered material on the rake face would lead to crater wear. Furthermore, the phenomenon of oxidation was also observed when machining at high cutting speed, which resulted in diffusion wear and increase in the crater wear. Based on the relationship between the cutting force and cutting temperature, it can be concluded that these machining outputs are significant in affecting the progression of tool wear rate, and tool wear mechanism in the machining of AISI 4340 alloy steel.

A series of experiments were conducted to assess the machinability of high density fiberboard using cemented carbide cutting tools. The objective of this work was to investigate the influence of two cutting parameters, spindle speed and feed per turn, on cutting forces, chip formation and cutting quality. The results are as follows: cutting forces and chip-breaking length decrease with increasing spindle speed and decreasing feed per turn. In contrast, surface roughness increases with decrease of spindle speed and increase in feed per turn. Chips were divided into four categories based on their shape: dust, particle, splinter, and semicontinuous chips. Chip-breaking length had a similar tendency to the variance of cutting forces with respect to average roughness and mean peak-to-valley height: an increase in the variance of cutting forces resulted in increased average roughness and mean peak-to-valley height. Thus, high cutting speed and low feed rate are parameters suitable for high-quality HDF processing and will improve not only machining quality, but production efficiency.

In order to increase the working efficiency of coated-carbide cutting tool under interrupted cutting conditions it is most efficient to use abrasion resistant refractory coating and solid lubricants.

The benefits of cutting fluids in machining are well known, but their use is accompanied by health and environment hazards. Moreover, strict environmental regulations make the manufacturers to switch over to dry turning, which is not feasible during machining of sticky material like stainless steel and Inconel etc. Therefore, the use of minimal quantities of lubricant (MQL) can be regarded as an alternative solution and a step towards green machining. In the present investigation an attempt has been made to explore the potential of MQL turning of stainless steel with coated carbide cutting tool. Turning under MQL conditions has shown superior results (in terms of flank wear and machined surface roughness) over wet and dry turning. Signal to noise (S/N) ratio as per Taguchi design revealed speed and MQL as significant parameters for minimizing flank wear and surface roughness, whereas feed can be set within range. The optimum combination of parameters are cutting speed (58 m/min), feed rate (0.06 mm/rev.) and MQL flow rate (100 mL/h) for flank wear and cutting speed (23 m/min), feed rate (0.07 mm/rev.) and MQL flow rate (150 mL/h) for surface roughness. Taguchi optimized conditions were validated through multiple response optimization using desirability function.

Carbon fiber reinforced plastic (CFRP) is an expensive composite which has become valuable material as the demand for this composite increased in the industries. It is suitable to be used in automotive, aerospace, and aircraft because of its properties which is stronger than steel and also stiffer than titanium while retaining its lighter weight. However machining of CFRP is a mess to machinist due to its nature which is abrasive. The paper presents the wear mechanism on solid carbide cutting tool during milling CFRP. The wear mechanism is observed under dry and chilled air machining. The machining parameters tested were at cutting speed of 200 m/min with constant feed rate and depth of cut. For both dry and chilled air machining, it is observed that carbide cutting tool experienced abrasive wear which has been influenced by abrasive powdering chips and fibers during milling CFRP. Under microscope and scanning electron microscope, the abrasive wear is represented by shiny and polish area on the cutting tool respectively. This abrasive wear is observed higher under dry machining compared to the chilled air machining which was due to the heat generated during machining. Thus, chilled air has a potential of improving machinability of CFRP by using solid carbide cutting tool.

A carbide cutting tool is widely used in machining process due to its availability and being cheaper than a better performance cutting tool, such as cubic boron nitride. The carbide cutting tool also has substantial hardness and toughness that is suitable to be applied in intermittent cutting. This paper presents the case study of a wear mechanism experienced on the cutting edge of the coated and uncoated carbide tools in turning and milling processes. The wear mechanisms of carbide cutting tools were investigated in machining Inconel 718, titanium alloy Ti–6Al–4V extra-low interstitial, and aluminum metal matrix composite (AlSi/AlN MMC) at their high cutting speed regime. The tools failed primarily due to wear on the flank and rake faces. The failure mode of the carbide cutting tools was similar regardless of the machining operations and coating is believed to enhance the tool life, but once removed, the tool fails similar to that with the uncoated tool.

A variety of cutting tool materials are used for the contact mode mechanical machining of components under extreme conditions of stress, temperature and/or corrosion, including operations such as drilling, milling turning and so on. These demanding conditions impose a seriously high strain rate (an order of magnitude higher than forming), and this limits the useful life of cutting tools, especially single-point cutting tools. Tungsten carbide is the most popularly used cutting tool material, and unfortunately its main ingredients of W and Co are at high risk in terms of material supply and are listed among critical raw materials (CRMs) for EU, for which sustainable use should be addressed. This paper highlights the evolution and the trend of use of CRMs) in cutting tools for mechanical machining through a timely review. The focus of this review and its motivation was driven by the four following themes: (i) the discussion of newly emerging hybrid machining processes offering performance enhancements and longevity in terms of tool life (laser and cryogenic incorporation); (ii) the development and synthesis of new CRM substitutes to minimise the use of tungsten; (iii) the improvement of the recycling of worn tools; and (iv) the accelerated use of modelling and simulation to design long-lasting tools in the Industry-4.0 framework, circular economy and cyber secure manufacturing. It may be noted that the scope of this paper is not to represent a completely exhaustive document concerning cutting tools for mechanical processing, but to raise awareness and pave the way for innovative thinking on the use of critical materials in mechanical processing tools with the aim of developing smart, timely control strategies and mitigation measures to suppress the use of CRMs.

Large thermal residual stresses in coatings during the coating deposition process may easily lead to coating delamination of coated carbide tools in machining. In order to reduce the possibility of coating delamination during the tool failure process, a theoretical method was proposed and a numerical method was constructed for the coating design of WC-Co cemented carbide cutting tools. The thermal residual stresses of multi-layered coatings were analytically modeled based on equivalent parameters of coating properties, and the stress distribution of coatings are simulated by Finite element method (FEM). The theoretically calculated results and the FEM simulated results were verified and in good agreement with the experimental test results. The effects of coating thickness, tool substrate, coating type and interlayer were investigated by the proposed geometric and FEM model. Based on the evaluations of matchability of tool substrate and tool coatings, the basic principles of tool coating design were proposed. This provides theoretical basis for the selection and design of coatings of cutting tools in high-speed machining.