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This article presents results obtained for the chipless cutting of wood using different cutting heads. Wood processing in forestry and the demand for firewood are currently increasing, so it is necessary to apply appropriate tools to the existing process, which will be sufficient for fast and highquality operations. Four groups of cutting knives were used for experimental measurements, where the influence of the cutting knife edge on the cutting process was determined. The cutting knives were always made of the same material and with the same blade angle - 30°. Measurements were made on spruce (Picea abies), beech (Fagus sylvatica), and willow (Salix caprea) trees. The size of the Fc cutting force was selected as the monitored variable, and then the dependent factors (kind of wood, wood diameter, cutting knife) were monitored in terms of their influence on the size of this Fc cutting force and thus also on the energy consumption. Based on the statistical evaluation, the most suitable shape of the cutting edge of the knife was selected, with this shape of the cutting edge, a reduction in the cutting force Fc was achieved for selected woods. [ABSTRACT FROM AUTHOR]

A sequential technique that combines wire electrical discharge machining (wire-EDM) and abrasive grinding on dedicated equipment improves the edge quality of boron-doped polycrystalline diamond (BD-PCD) cutting tools. In this study, we focus on material removal mechanisms during BD-PCD machining and surface graphitization caused by wire-EDM thermal damage. Surface topography is used to distinguish ductile- and brittle-regime grinding in tool production. Resin-bonded diamond wheels outperform electroplated diamond wheels in abrasive grinding owing to their self-sharpening capabilities. The experimental results show that BD-PCD tools have higher mechanical properties and performance than standard PCD tools. Maximum edge chipping on BD-PCD surfaces depends on the depth of cut and grinding speed. Microgrinding experiments on BK7 glass reveal that the recommended tool manufacturing approach, which merges wire-EDM and abrasive grinding, results in high-quality surfaces free of microcracks and achieves a surface roughness of 6 nm Sa. Abrasion on the flank face and chipping on the periphery are the main wear patterns on grinding tools. In this study, we improve our understanding of BD-PCD microcutter production, focusing on parameter management for optimal surface quality, edge integrity, and tool performance. We emphasize the necessity of choosing the right grinding wheel to achieve the necessary surface and subsurface quality when making microcutting tools. Raman spectroscopy results are used to explain thermal deterioration when diamond grains turn into graphite at high manufacturing temperatures. We address the challenges of producing high-quality microcutting tools and offer insights into improving BDPCD tool performance and edge quality. [ABSTRACT FROM AUTHOR]

This article presents results obtained for the chipless cutting of wood using different cutting heads. Wood processing in forestry and the demand for firewood are currently increasing, so it is necessary to apply appropriate tools to the existing process, which will be sufficient for fast and high-quality operations. Four groups of cutting knives were used for experimental measurements, where the influence of the cutting knife edge on the cutting process was determined. The cutting knives were always made of the same material and with the same blade angle ∢ 30°. Measurements were made on spruce (Picea abies), beech (Fagus sylvatica), and willow (Salix caprea) trees. The size of the Fc cutting force was selected as the monitored variable, and then the dependent factors (kind of wood, wood diameter, cutting knife) were monitored in terms of their influence on the size of this Fc cutting force and thus also on the energy consumption. Based on the statistical evaluation, the most suitable shape of the cutting edge of the knife was selected, with this shape of the cutting edge, a reduction in the cutting force Fc was achieved for selected woods.

Circular open caissons are deep foundations sunk into the ground utilising the self-weight of cutting edge and steining as driving force along with the subsequent failure of soil in bearing. During the sinking of the caisson, the clay in contact with the cutting edge is subjected to undrained loading and the controlled sinking of the caisson can be achieved by evaluating the undrained bearing capacity of the cutting edge. In the study, the undrained bearing capacity factor (N) of the cutting edge for varying cutting angle (b), radius ratio of the caisson (ri/ro), full embedment of the caisson (d), removal of soil within the caisson (d'), and different roughness (α) conditions of the steining are evaluated using finite element limit analysis (FELA). The factors affecting the undrained stability of caisson considering all practical scenarios are addressed and presented as charts to be used in practice. [ABSTRACT FROM AUTHOR]

Open caissons are commonly used in the construction of various underground structures, such as launch and reception shafts for tunnel-boring machines, storage or attenuation tanks, and cofferdams. During the sinking phase, the cutting edge of a caisson wall with a cutting face encounters soil and is subjected to loading to facilitate and control the sinking process. In this regard, the bearing capacity factor (N) of the cutting face of a circular open caisson in heterogeneous clay is evaluated via finite element limit analysis, which accounts for the increase in the undrained shear strength with depth. The parameters considered in this study cover practical aspects, including the excavation geometry, soil strength profile, and caisson geometry. This investigation also explored the impacts of the cutting face angle (β), roughness (α), ratio of the internal embedment depth to the embedment width (H/B), ratio of the internal radius to the embedment width (R/B), and strength gradient ratio (ρB/su0). In particular, when the H/B > R/B ratio, the N value tends to stabilize. Crucially, when H/B > 4, an increasing trend in R/B leads to a rise in N until R/B exceeds 10, i.e., large diameter caissons, stabilizing the N value. Furthermore, the results reveal the significant dependency of the cutting face roughness and strength gradient ratio of clay on N. The artificial neural network model, which is a soft computing-based model, is also developed to present the undrained bearing capacity forecasting equation. Compared with conventional regression, including the multiple linear regression model and the multiple nonlinear regression model, it has excellent performance, as measured by eight indices. In addition, ANOVA and Z-tests can support the research hypothesis and reject the null hypothesis. [ABSTRACT FROM AUTHOR]

The edge area is especially essential for cutting tools, since this is the contact zone between the work piece and the tool. Hard coatings (PVD or CVD coatings) can protect the edge against wear and they are commonly used. The geometries of the cutting edges change during the coating process, with the edge radius increasing. Therefore, the film thickness is limited and the initial radius of the uncoated tool must be smaller than the target radius of the coated edge. A new coating process based on vacuum arc PVD was developed to overcome this limitation. The film growth at the edges can be properly controlled by means of selected coating materials and process conditions. Thus, it is possible to grow edges sharper than the initial edge geometry. Different substrates were coated with different coating systems. Parameters such as the bias voltage, coating pressure, and initial radius were varied within this work. It was found that the application of a bias voltage is crucial for the generation of sharp edges. It was also found that the edge sharpening caused by coatings works best on samples with an initial radius of around 15 µm. [ABSTRACT FROM AUTHOR]

Purpose: In modern industry, titanium is recognised for its remarkable wear resistance and strength. However, its poor thermal conductivity poses a problem because it shortens the life cycle of cutting tools. Researchers have focused on enhancing the service life of cutting-edge tools, cutting production costs by using new coating materials, and identifying appropriate materials for these coatings. Design/methodology/approach: The experimental design involved tests with controlled cutting speeds of 150, 175, 200, and 225 m/min, feed rates of 0.2, 0.25, and 0.30 mm/rev, and cutting depths of 0.5, 1.0, and 1.2 mm. Titanium with a diameter of 25 mm and a length of 200 mm was prepared for the turning test over a machining distance of 20 mm. The chips obtained from the cutting test were observed and analysed using a scanning electron microscope to investigate the effect of the tool coating on the characteristics of the chip formation mechanism. Findings: The study revealed that inserts coated with AlCrSiTiN produced the characteristic of long twisted chips transitioning into continuous chips with shorter twisting distances than uncoated cermet inserts. The uncoated cermet inserts resulted in a greater twisting distance based on an examination of the chips with a scanning electron microscope, revealing more pronounced jaggedness in the fragments produced by the cermet turning inserts, which also possessed a larger average clearance than the inserts coated with AlCrSiTiN and TiAlSiN. Furthermore, the uncoated cermet inserts showed less wear at lower cutting speeds than the other types of inserts. Conversely, the TiAlSiN-coated inserts exhibited less wear at higher cutting speeds than the inserts of different materials. Research limitations/implications: The triangularly shaped inserts were cermet inserts coated with AlCrSiTiN or TiAlSiN via the PVD method and were used for dry turning. Practical implications: Wear of cutting-edge tools is a problem in turning of titanium. Therefore, it is crucial to identify methods to minimise wear and extend the service life considering the investment worthiness. Likewise, efforts are being made to develop new coatings tailored to the materials. Originality/value: The research could provide guidelines for reducing the wear generated in cutting tools and increasing the service life of cutting edges by adjusting the machining parameters. [ABSTRACT FROM AUTHOR]

The objective of this work was to investigate the rate of knife wear during the beech wood chipping process and to evaluate the changes in the chemical and microscopic structure of wood. A knife coated with AlCrN was selected for the study. This coating creates an abrasion resistant layer on the knife and has a higher resistance to abrasive wear and, therefore, a longer life. After chipping, the degree of knife wear was assessed using a gravimetric method and 3D scanning analysis. Microstructural and surface characterisation revealed that cracking and abrasive wear were the main causes of tool blunting. The maximum removal of material on the cutting edge was 240 µm, the average weight loss of 0.58 g. In relation to wear, wood fragments remained on the cutting knife. Infrared spectroscopy of wood fragments showed changes in the chemical composition due to the high temperatures in the blade of the knife, and elemental analysis, the higher content of Al, Cr, and N elements in the wood fragments, probably due to the presence of particles from the coating of the knives. Microscopic analysis of the chips revealed the presence of metal particles from the knives on the structural wood elements. [ABSTRACT FROM AUTHOR]

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Typical edge defects in the edge region of a new cemented carbide insert without edge preparation include burrs, poor surface quality, micro-breakages, and irregularities along the edge. To address the problems in new cemented carbide inserts without edge preparations, a chemical–mechanical synergistic preparation (CMSP) method for the cemented carbide insert cutting edge was proposed. Firstly, the CMSP device for the insert cutting edge was constructed. Then, the polishing slurry of the CMSP for the insert cutting edge was optimized using the Taguchi method combined with a grey relation analysis and fuzzy inference. Finally, orthogonal experiments, the Taguchi method, and analysis of variance (ANOVA) were used to investigate the effect of the polishing plate's rotational speed, swing angle, and input frequency of the controller on the edge preparation process, and the parameters were optimized. The results showed that the best parameter combination for the polishing slurry for the cemented carbide inserts was the mass concentration of the abrasive particle of 10 wt%, the mass concentration of the oxidant of 10 wt%, the mass concentration of the dispersant of 2 wt%, and the pH of 8. The CMSP process parameter combination for the linear edge had the polishing plate's rotational speed of 90 rpm, the swing angle of 6°, and the input frequency of the controller of 5000 Hz. The optimum CMSP process parameter combination for the circular edge had the polishing plate's rotational speed of 90 rpm, the swing angle of 6°, and the input frequency of the controller of 7000 Hz. The polishing plate's rotational speed had the most significant impact on the edge preparation process, followed by the swing angle, and the effect of the input frequency of the controller was the smallest. This study demonstrated that CMSP is a potential way to treat the cemented carbide insert cutting edge in a tool enterprise. [ABSTRACT FROM AUTHOR]

Titanium alloy is widely used in typical aerospace structural parts because of its excellent mechanical properties and corrosion resistance. However, the serious problem of tool wear in the machining process of titanium alloy often leads to the decline of machining quality. In this article, scCO2 MQL cutting experiment and dry cutting experiment of TC11 are carried out. The machined surface morphology, plastic deformation, residual stress and tool wear were analyzed. The results show that scCO2 MQL can effectively reduce the surface defects on the machined surface. The increase of cutting edge structure and blunt radius of the composite increases the plastic deformation degree of the material, as well as the residual stress and work hardening degree. The scCO2 MQL can effectively improve the cutting contact area and reduce tool joint wear. [ABSTRACT FROM AUTHOR]

In this study, a novel design scheme for a power skiving cutter and its grinding wheel profile is proposed based on the geometry of a target circular spline (CS) workpiece. First, a generalized mathematical model of a target CS profile is expressed using a B-spline curve. Subsequently, the nominal cutting edge of the skiving cutter for generating an error-free CS is derived based on power skiving kinematics. In addition, the axial profile of the grinding wheel for generating the derived nominal cutting edge is resolved based on lengthwise-reciprocating grinding kinematics. The proposed design process for the skiving cutter and its grinding wheel is illustrated using numerical examples. The profile accuracy of the CS yielded by the designed nominal cutting edge is computed to validate the proposed design processes. Moreover, errors of the skived CS profile resulting from various resharpening depths by grinding back the stepped rake face of the skiving cutter are investigated. Finally, to effectively extend the tool life of the skiving cutter, a compensation rolling angle is introduced into the CS skiving process. [ABSTRACT FROM AUTHOR]

Chain trench excavators are widely used in the world for trenching in agriculture, laying underground cables, digging trenches. In this study, the research object is a small chain-type trench excavator. The purpose of the study is to evaluate and select the parameters of the chain loader to the machine productivity and evaluate the results of the experimental machine theory calculation. Experimental measurement parameters include machine speed when working, chain speed, blade distance adjustment on the chain. Research method is to conduct experiments using Taguchi method to design experiments and Minitab software to analyze data. Experimental results and numerical analysis determined that the optimal set of parameters was the distance of 2 cutting edges on the chain, the active sprocket rotation speed for the highest productivity. Compared with the results from the theory using the design, the deviation of the optimal parameters is less than 5%. Experimental process design and parameter influence analysis by Taguchi method, ANOVA analysis have identified reasonable parameters, highest productivity target. [ABSTRACT FROM AUTHOR]

This study presents a thorough experimental investigation utilising the design of experiments and analysis of variance (ANOVA) to examine the impact of machining process parameters on chip formation mechanisms, machining forces, workpiece surface integrity, and damage resulting from the orthogonal cutting of unidirectional CFRP. The study identified the mechanisms behind chip formation and found it to significantly impact the workpiece orientation of fibre and the tool's cutting angle, resulting in increased fibre bounceback at larger fibre orientation angles and when using smaller rake angle tools. Increasing the depth of cut and fibre orientation angle results in an increased damage depth, while using higher rake angles reduces it. An analytical model based on response surface analysis for predicting machining forces, damage, surface roughness, and bounceback was also developed. The ANOVA results indicate that fibre orientation is the most significant factor in machining CFRP, while cutting speed is insignificant. Increasing fibre orientation angle and depth leads to deeper damage, while larger tool rake angles reduce damage. Machining workpieces with 0° fibre orientation angle results in the least subsurface damage, and surface roughness is unaffected by the tool rake angle for fibre orientations between 0° to 90° but worsens for angles greater than 90°. Optimisation of cutting parameters was subsequently carried out to improve machined workpiece surface quality and reduce forces. The experimental results showed that negative rake angle and cutting at moderately low speeds (366 mm/min) are the optimal conditions for machining laminates with a fibre angle of θ = 45°. On the other hand, for composite materials with fibre angles of θ = 90° and θ = 135°, it is recommended to use a high positive rake angle and cutting speeds. [ABSTRACT FROM AUTHOR]

The cutting part of mills determines their operational efficiency and the product quality. The cutting edges of mills with complex production surfaces have special design features as a result of intersection of the helical rake surfaces with the rear surface. Accordingly, in this case standart monitoring of the cutting edges' geometry is problematic. In the present work, a method is proposed for monitoring of the cutting edges by means of machine vision. The new method is based on algorithms and models expressing the functional relations between the design parameters and the mechanism for image capture and recognition. These parameters ensure monitoring of the dimensional precision and the chipping of the mill's edges. The algorithm optimizes the range of image capture by assessing he difference in color intensity and detects points on the wear edge within the horizontal observation regions for the boundary of the edge or chip. The measurement error was incorporated into the CAD design of mills with a shaped cutting surface. A Walter Helicheck Plus high-precision system is used for experiments and verification of the precision measurements at the end mill's cutting edges. The proposed method is universal and can greatly simplify the measurement of multicutter mills. [ABSTRACT FROM AUTHOR]

Separating two or more aspects of an object via cutting was likely an important factor in the origin and evolution of flaked stone technology. In recent years experiments have demonstrated that several stone tool attributes can influence different kinds of cutting behaviour: slicing, cleaving, scraping, sawing, drilling, piercing and abrading. Here we experimentally assessed the role of stone flake plan‐ and profile‐view gross‐edge curvature in a controlled slicing task. We also assessed the role of edge length. A total of 21 participants, using 252 stone flakes with distinct gross‐edge curvatures and edge lengths, were asked to cut through a standardized substrate, and their efficiency in the task was measured over time. Flakes with longer edge lengths increased the efficiency of the cutting task, but increasing either plan‐ or profile‐view edge curvature decreased the efficiency of the cutting task. These results have implications for the emergence of particular tool forms or reduction sequences throughout the Pleistocene, and may in part explain why certain forms were favoured by Paleolithic people, leading to their convergent evolution or widespread transmission. [ABSTRACT FROM AUTHOR]

In BTA (Boring and Trepanning Association) deep hole drilling the resulting surface and subsurface zone of the bore are conditioned by two main components of the tool, the cutting edge and the guide pads. To differentiate the influence of the components, experiments in an analogue model setup were conducted only using the cutting edge. Different cutting edge designs and process parameters were used during the machining experiments to determine the influence on the surface integrity. Using non-destructive measurement techniques, the specimens were analyzed regarding the residual stress state and the surface roughness. The model-experiment-based results are compared to investigations of the surface integrity in original BTA deep hole drilling. [ABSTRACT FROM AUTHOR]

The wear behaviour of cutting tools can be significantly improved by a load-optimized design of the cutting edge microgeometry. Thereby, the knowledge of local mechanical stresses is necessary. The experimental-based modelling of mechanical stresses in the continuous cut was already investigated in previous work. In this paper, this method is adapted to the interrupted cut by considering contact lengths, process forces and process temperatures during tool entry and exit. The identified mechanical stresses and temperatures are used for a tool material specific cutting edge microgeometry design. [ABSTRACT FROM AUTHOR]

Technological gadgets, methods, and accomplishments that make use of the most recent and advanced IT advances are examples of cutting-edge technology. "Cutting edge" is a term commonly used to describe the most advanced and forward-thinking companies in the IT industry. The term "cutting-edge technology" is used to describe the most advanced and up-to-date technological features, as opposed to "bleeding-edge technology," which is so novel that it presents risks to consumers. While the term "technology" is most often associated with computer and electronic devices, it can refer to advancements in virtually any field. The author of this paper has properly cited the most up-todate cutting-edge research. [ABSTRACT FROM AUTHOR]

Nickel-based superalloy has great potential in the aerospace industry as key components. However, difficult-to-machine characteristics have further limited its application. Thermal-barrier coatings of the titanium-based family on carbide tools offer exceptional performance in cutting superalloys, combining high-temperature stability and remarkable toughness. This work primarily concentrates on understanding cutting-edge microstructure and deformation induced by tool adhesive wear in the turning of nickel-based superalloys with experiment and modelling. The dominant tool wear mechanisms are revealed to be adhesive wear and abrasive wear by SEM/EDS. The microstructure of the cutting-edge interface is qualitatively and quantitatively investigated by SEM/EDS and EBSD. The adhesive layer thickness at cutting edge is about 10–30 μm. The GND density of WC grains at cutting edge is 15-20 × 1014/m. The nanomechanics properties of the tool wear interface were quantitatively evaluated by nanoindentation. The average hardness of WC and Ni-superalloy at cutting-edge interface is evaluated to be 15–19 GPa and 6.2–6.5 GPa, respectively. Further, the underlying deformation mechanisms induced by tool wear behaviours are revealed through the transient heat conduction model and cutting-edge stress distribution model. This research offers a framework and mechanism for the cutting tool wear surface/interface characteristics targeted to the difficult-to-cut superalloy materials. • The dominant tool surface wear mechanisms are revealed to be adhesive wear and abrasive wear. • The adhesive layer thickness at cutting-edge interface is about 10–30 μm. • The average hardness of WC and Ni-superalloy at cutting-edge interface are 15–19 GPa and 6.2–6.5 GPa. • Cutting-edge deformation mechanisms are revealed by the heat conduction model and stress distribution model. [ABSTRACT FROM AUTHOR]

Typical edge defects in the edge region of a new cemented carbide insert without edge preparation include burrs, poor surface quality, micro-breakages, and irregularities along the edge. To address the problems in new cemented carbide inserts without edge preparations, a chemical–mechanical synergistic preparation (CMSP) method for the cemented carbide insert cutting edge was proposed. Firstly, the CMSP device for the insert cutting edge was constructed. Then, the polishing slurry of the CMSP for the insert cutting edge was optimized using the Taguchi method combined with a grey relation analysis and fuzzy inference. Finally, orthogonal experiments, the Taguchi method, and analysis of variance (ANOVA) were used to investigate the effect of the polishing plate’s rotational speed, swing angle, and input frequency of the controller on the edge preparation process, and the parameters were optimized. The results showed that the best parameter combination for the polishing slurry for the cemented carbide inserts was the mass concentration of the abrasive particle of 10 wt%, the mass concentration of the oxidant of 10 wt%, the mass concentration of the dispersant of 2 wt%, and the pH of 8. The CMSP process parameter combination for the linear edge had the polishing plate’s rotational speed of 90 rpm, the swing angle of 6°, and the input frequency of the controller of 5000 Hz. The optimum CMSP process parameter combination for the circular edge had the polishing plate’s rotational speed of 90 rpm, the swing angle of 6°, and the input frequency of the controller of 7000 Hz. The polishing plate’s rotational speed had the most significant impact on the edge preparation process, followed by the swing angle, and the effect of the input frequency of the controller was the smallest. This study demonstrated that CMSP is a potential way to treat the cemented carbide insert cutting edge in a tool enterprise.

The shape of the cutting blades of the abrasive grains has an influence on the material separation process in the machining zone. The paper analyzes the influence of the geometrical parameters of the abrasive grains (rake angle γ, apex angle ε, opening angle α), as well as width bz and length bb of the cutting zone on the material removal efficiency. The material removal efficiency was determined taking into account the volume of the removed material VG and the volume of lateral piles-up VR. The analyses were carried out on the basis of the results of experimental and simulations using the finite element method. The relationship between the selected geometric parameters characterizing the cutting zone and the coefficient characterizing the efficiency of the material removal process was determined. A strong influence of the opening angle α as well as the width bz and length bb of the cutting zone on the material removal process by abrasive grain was demonstrated. It was observed that the wide cutting edge, and thus the large opening angle α of the grain, reduced the size of the pile-ups and more effectively removed the chip material. [ABSTRACT FROM AUTHOR]

Open caissons are massive foundations sunk to the required depth by excavating the soil in contact with the cutting edge of the caisson through the annular space of the shaft. The sinking of caisson initiates when the soil in contact with the cutting edge fails in bearing. The evaluation of bearing capacity of the cutting edge helps in proper planning of the excavation strategy, analysis and design of caissons. In the present study, the bearing capacity factors for the cutting face of open caisson are evaluated using finite element method for different configurations of the cutting edge, properties of the soil and depth of sinking. The cutting edge with varying radii ratio (ri/ro = 0.35 to 0.95) and different cutting angles (β = 30° and 45°) is considered. The Mohr–Coulomb model with non-associated flow rule is used in the two-dimensional finite element (FE) analysis. The bearing capacity factors for the cutting face of the open caisson are evaluated for different friction angles of the soil (ϕ = 5° to 35°). The depth of sinking is accounted for in the FE analysis by considering the soil present above the base of the cutting edge as surcharge. The present FE results are compared with the results available in the literature and presented in the form of ready-to-use charts and tables for design purposes. [ABSTRACT FROM AUTHOR]

Through the use of tool coatings, a significant increase in tool life is possible. Particularly in the case of coatings obtained by physical vapor deposition, compressive residual stresses show a clearly positive influence on the wear behavior of coated carbide tools. In addition to being influenced by the coating process itself, the residual stress state of the coating can also be influenced by post-treatment processes like heat treatment or wet blasting. Compressive residual stresses can be measured using known X-ray diffraction techniques. However, these methods are very limited on strongly curved surfaces such as cutting edges. Raman spectroscopy has great potential for measurements in such areas. In order to use the Raman method to measure residual stresses on cutting tools, the TiAlN coatings were subjected to wet blasting and heat treatment. The residual stress state was determined by X-ray diffraction using the sin2ψ method and the depth-resolved scattering vector method. Then, measurements of Raman scattering of light were carried out and the peak shift of the transversal/longitudinal optical mode in the Raman spectrum was measured. Finally, the peak shift in the cutting edge area was determined. The investigations show that residual stresses mechanically induced by wet blasting can be reliably detected by Raman spectroscopy. Heat treatment effects are also clearly detectable, but here the correlation between peak shift and residual stresses determined by X-ray diffraction methods differs from the previous results due to the change in the crystal lattice dimensions. The residual stresses in the cutting edge area, converted from Raman peak shifts, show values of a plausible order of magnitude. [ABSTRACT FROM AUTHOR]

The presence of micro-cracks and serrations on the tool often leads to its premature failure. However, these microscopic defects can be mitigated through passivation treatment of the tool. Magnetoelastic abrasive particles are new composite particles formed by using abrasive phase particles, magnetic media phase particles and polymer matrix according to a certain ratio, the abrasive particles have both viscoelasticity and magnetic conductivity. The introduction of magnetoelastic abrasive grains into the dual-disk tool passivation equipment can effectively improve the surface quality of the tool and increase the passivation efficiency. At the outset, a model for tool passivation was crafted employing the ABAQUS simulation software. This model aimed to evaluate the effects of diverse passivation variables on the stress levels, the shape of the impact, and the depth of the impact experienced by the tool. Subsequently, by applying statistical theory combined with fitting function techniques, a mathematical model was constructed to determine the passivation volume of the tool subjected to multiple magnetic elastic abrasive particles. This model was then used to examine the impact count and passivation volume associated with each passivation factor. Finally, a tool passivation experiment was conducted using a dual-disk magnetic tool passivation device. The results showed that the smaller the impact velocity of magnetic elastic abrasive particles, the stress and impact depth of the cutting tool are decreasing, and the deformation of the cutting edge is caused by compressive stress. The error of impact depth calculated by simulation and mathematical model is within 20 %, which proves that the mathematical model can better calculate the impact depth of magnetic elastic abrasive particles on the cutting edge of the tool. [ABSTRACT FROM AUTHOR]

In the manufacture of metal parts, it is crucial to measure the tool wear accurately and quickly to improve machining automation, avoid tool change error, and perform tool wear compensation. In this study, an image-based on-machine and direct measurement model is proposed for the circumferential cutting edge wear of a milling cutter. First, a charge-coupled device sensor is applied to collect the one-dimensional (1D) projected images of the cross section on a circumferential cutting edge. The multiple-frame 1D images under one rotation angle of cutter are stitched into a rectangular image. Then, the multiple rectangular images in one rotation of the cutter are stitched to form a two-dimensional (2D) image. Also, the image edges are positioned through the image edge detection algorithms. Finally, based on the outer edges of the rectangular images for a same cutting edge, the tool diameter is measured; from the relationship of the radius wear and the flank wear on a circumferential cutting edge, the flank wear is obtained. The improved watershed algorithm based on the marked grayscale gradient image, the pixel level positioning algorithm based on Sobel operator, and the sub-pixel level positioning algorithm based on the grayscale moment are adopted for image edge detection. The performed experiments validate that the proposed image-based method is an effective way for measuring wear of the circumferential cutting edge of a milling cutter. [ABSTRACT FROM AUTHOR]

Introduction. Grinding sugar beet should be carried out with minimal losses in centrifugal beet cutters with specially designed knives that provide frequent and constant chaotic longitudinal-lateral cutting of circular conductive beet knots. The objective of the work is to increase the reliability of the knives of centrifugal beet cutters by structural and technological strengthening in the process of their production and restoration. Materials and Methods. The state of the cutting edges of the knives was determined by using the micrometric measurement of the wear and deformation of the edges. Physical and mechanical indicators were analyzed based on the values of wear resistance, microhardness, and bending endurance. Results. The analyzes of the defective state of the knives of centrifugal beet cutters and theoretical studies of the grinding process have allowed formulating the factors affecting the permeability of the beet chips and the efficiency of their grinding with knives of a special diamond-shaped design. Experimental studies have made it possible to establish dynamically substantiated design parameters of an improved knurled knife. Discussion and Conclusion. The proposed measures ensured an increase in the durability of knives by 27–30%, the relative wear resistance of cutting edges by 20%, the limit of endurance of cutting edges for bending by 25% and a shift increase in the length of chips by 18–20% with an increase in its permeability by 16–18%.

A significant part in the structure of production costs associated with restoring the current operability of locomotive wheels by processing on the KJ20 machine is amounted by tool costs. The cost of the tool, especially hard-alloy, is constantly increasing. The restoration of the working capacity of hard-alloy cutting elements is carried out by turning them in the tool holder (knife) at a certain angle around the axis of this element. The new technique for the effective use of special shaped mills is based on determining the rational angle of rotation of the cutting elements. A promising direction for the use of cutting elements is also the restoration of the properties of worn elements for their reuse. EDM processes are especially effective in tool production in the manufacture of special tools. The authors developed and proposed a technology for restoring the working capacity of cutting elements that have already worked out their resources. The technology proposed by the authors makes it possible to introduce a system of cost-effective and rational operation for the use of part of worn out, but suitable for restoration, replaceable cutting elements, for their reuse in the repair of the working surface of wheelsets of rail vehicles on KJ20 machines.

The machining of a deep hole by a gun drill is considered, both theoretically and experimentally. The cutting zone is divided notionally into 20 annular layers, for each of which the cutting parameters are calculated by successive approximation. A formula permits estimation of the cutter's wear facet, taking account of the energy consumed, the tool parameters, and the machining time. [ABSTRACT FROM AUTHOR]

This paper, in deviation from the traditional practices of textbook evaluation, reports the faculty members' evaluation of Cutting Edge, Student Book, KSA Third Edition Intermediate Level, by Sarah Cunningham & Peter Moor, published by Pearson 2013 in terms of Language Development Skills, in general, and, Listening, Speaking, Reading, Writing, Grammar & Vocabulary, and Style & Appropriacy in particular. 20 EFL teachers participated in this mixed method approach of study who work at the Department of English Skills, Preparatory Year, Najran University, Saudi Arabia. A google form questionnaire, consisted of 57 numerically rated items & open-ended questions under 7 domains, was created to elicit faculty members' responses. The validity of the questionnaire was examined by a group of experts in the textbook evaluation and content analysis. The analysis indicates that the respondents evaluated the textbook contents positively and the majority viewed them mostly suitable in terms of language skills, usage, and appropriacy. However, the researcher, based on the adverse comments like video material for listening, lack of specific strategies for conversation or other spoken activities, and hardly distinction between active and passive vocabulary under listening, speaking and grammar & vocabulary domains, suggests that a latest EFL commercial textbook or series be reviewed which, potentially, will cover the space. To conclude, the researcher recommends developing authentic materials that are tailored to the needs and interests of the learners. [ABSTRACT FROM AUTHOR]

The article compares two cutting edge preparation methods and their influence on the machined surface roughness of the difficult to cut nickel alloy Inconel 718 and the tool wear of cutting inserts made of cemented carbide. The manufacturing and preparation process of cutting inserts used in the experiment were made by Dormer Pramet. The preparation methods used in the experiment were drag finishing and brushing. Cutting parameters did not change during the whole turning process to maintain the same conditions in each step of the process and were determined based on tests for a semifinishing operation of the turning process. To obtain durability of 25 to 30 minutes with controlled development of the tool wear the cutting parameters were determined with cooperation with the cutting inserts manufacturer. [ABSTRACT FROM AUTHOR]

This paper proposes a novel scheme titled ‘selective exchange of the worn cutting edge (SEWCE),’ which uses the cutting edge for an extended time by replacing the worn-out edge. This possibility was investigated for single-edge cutting tools for several operations, such as oblique and orthogonal cutting. The unique design of the turning tool incorporating cylindrical inserts was developed, thereby providing new machining possibilities compared to marketed solutions for round inserts. The prototype tool was prepared for the demonstration by using a cylinder with radius rε = 1.5 mm. A detailed analysis of the contact-zone cutting edge was performed considering a theoretical number of edges for different strategies. With this, the possibility for reusing the cutting element by resharpening the rake surface by up to ‘20x’ was achieved. Additionally, round inserts can be efficiently used in this developed scenario by turning them to compensate for the worn parts of the cutting tools. Therefore, by rotating, the deformed section of the cutting tool can be eliminated, and the number of edges can be created, directly reducing tool costs. Ultimately, conserving the health of a cutting tool brings many advantages, such as extending useful remaining lifetime, improving the surface quality and dimensional accuracy of machine parts, etc.

Machining abrasive carbon fibre reinforced polymers (CFRP) is characterised by extensive mechanical wear. In consequence, the cutting edge micro-geometry and thus the tool/material contact situation are continuously changing, which affects process forces and machining quality. As a conclusion, a fundamental understanding of the tool wear behaviour and its influencing factors is crucial in order to improve performance and lifetime of cutting tools. This paper focuses on a fundamental tool wear analysis of uncoated tungsten carbide cutting inserts with different combinations of fibre cutting angles and tool geometries. For this purpose, orthogonal machining experiments with unidirectional CFRP material are conducted, where the wear progression of the micro-geometry is investigated by means of five wear parameters lα, lγ, γ*, α*, and bc. For detecting the actual contact zone of the cutting edge and to measure the elastic spring back of the material, the flank face is marked via short pulsed laser processing. Furthermore, the process forces and the wear rate are measured. It is shown that the material loss due to wear clearly varies along the tool's contact region and is highly dependent on the clearance angle and the fibre cutting angle Φ, while the influence of the tested rake angles is mostly negligible. Especially in machining Φ=30° and Φ=60°, a strong elastic spring back is identified, which is more intense for smaller clearance angles. For all tested configurations, the material's elastic spring back increases in intensity as wear progresses which, in combination with the decreasing clearance angle, is the main reason for high thrust forces. [ABSTRACT FROM AUTHOR]

The efficiency of sugar production depends largely on the state of beet chips obtained from a centrifugal sugar beet cutter. It is shown that a one-shift operation of defective knives may result in a loss of up to 28-30 percent of sucrose. (Research purpose) To establish quality indicators of beet chips obtained from a centrifugal beet cutter, to improve a design and production technology of knives with increased physical and mechanical characteristics. (Materials and methods) The authors identified the reasons leading to the deterioration of the knife parameters and ensuring the quality of sugar beet cutting. To increase the indicators of wear resistance and bending strength of the cutting edges, the knife design was modified and a new technology of knife manufacturing was offered. The authors theoretically and experimentally proved the feasibility of replacing the manufacturing technology of the cutting edges of knives - from cutting to plastic deformation in die tooling. (Results and discussion) The authors have determined the mechanism and consequences of the wear and breakage of cutting points and the deformation and breakage of cutting edges of sugar beet knives. The technology of edge die stamping with special equipment was offered. The design of tooling for die stamping and machining of knife’s cutting edges was developed and experimentally tested in production conditions. (Conclusions) The authors offered the methods of strengthening cutting edges of knives with die casting, as well as offered solutions to the design problems of knife manufacturing using special high-performance and resource-saving equipment. The main physical and mechanical characteristics of sugar beet knives manufactured according to conventional and improved technologies have been experimentally determined and tested under operating conditions. The authors show the advantages of the cutting edges of sugar beet knives manufactured according to the improved technology; the study has proved an increase in microhardness by 14 percent and an increase in bending strength by 30 percent.