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The present research analyses the power consumption (Pc) and surface roughness (Ra) in hard turning of high‐strength low‐alloy (HSLA) grade AISI 4140 steel using a recently developed AlTiSiN‐coated carbide tool under different cooling‐lubrication conditions (dry, flooded, nanofluid‐MQL). The nanofluid was prepared by mixing the MWCNT nanoparticles with an eco‐friendly automotive radiator coolant (base fluid). The cooling‐lubrication performance is investigated briefly by comparing the machining responses like machined surface morphology, tool wear, cutting force and temperature. The experiments associated with 46 trials were performed by considering various machining variables, namely cutting speed, nose radius, depth of cut, feed and cooling‐lubrication methods. From the perspective of predictive modelling and multi‐response optimisation, response surface methodology has been employed to minimise power consumption and surface roughness. Thereafter, the predictive modelling and optimisation results are implemented for economic analysis and energy‐saving carbon footprint evaluation. This innovative research also addresses comparative environmental sustainability evaluation in hard turning under different cooling‐lubrication conditions using a life cycle assessment methodology for cleaner and safer production. Results indicate that cutting speed was the most influential item in power consumption enhancement. Furthermore, compared with dry and flooded turning, lower cutting force, reduced cutting temperature, shorter width of flank wear and better surface morphology were obtained under nanofluid‐MQL machining. It has been observed that nanofluid‐MQL machining outperformed sustainability improvement concerning techno‐economically viable societal acceptable and environmental friendliness. [ABSTRACT FROM AUTHOR]

In the modern world of competitive manufacturing, turning is a basic and important process that needs to be optimized for the fast-evolving industrial nature. It has its application in various fields involving numerous materials. This research study deals with modeling with optimization on the turning process parameters of turning E2-BS970 mild steel with cryogenically treated tungsten carbide tool under NFMQL having SiC + MoS 2 nanofluid. The parameters considered as the input factors are spindle speed and depth of cut along with feed rate and lubrication condition. The design of the experiment is done based on Box–Behnken design for 27 trials in the response surface method. The Deep Neural Network (DBN) and the Coot optimization algorithm are employed using MATLAB software for the prediction modeling. The prediction model developed by the DBN sigmoid function gave minimal error with prediction regression values of 0.99988 for MRR, 0.99516 for Cutting temperature, and 0.99545 for Tool life. The optimized result by CO shows a value of 188.89 rpm for spindle speed, 0.2318 mm/rev for feed rate, Doc of 1.45 mm, and 0.5015 vol.% nanofluid MQL condition. The optimized values of MRR are 3.35 mm3/min, 2 4. 1 4 5 ∘ C cutting temperature, and 1543.12 s of tool life. The DBN model combined with the Coot algorithm shows minimal deviation compared to the experimental results validation and confirmatory analysis and is deemed suitable for efficient prediction. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to examine the cutting performance of a coated carbide tool during the boring of 1Cr17Ni2 martensitic stainless steel, with a focus on how the tool's structural parameters, particularly the nose radius, affect the wear patterns, wear volume and lifetime of the cutting tool, and related mechanisms. Design/methodology/approach: A full factorial boring experiment with three factors at two levels was conducted to analyze systematically the impact of cutting parameters on the tool wear behavior. The evolution of tool wear over the machining time was recorded, and the influences of the cutting parameters and nose radius on wear behavior of the tool were examined. Findings: The results show that higher cutting parameters lead to significant wear or plastic deformation at the tool nose. When the cutting depth is less than the nose radius, the tool wear tends to be minimized. Larger nose radius tools have weaker chip-breaking but greater strength and wear resistance. Higher cutting parameters reduce wear for the tools with larger nose radius, maintaining their integrity. Wear mechanisms are primarily abrasive, adhesive and diffusion wear. Furthermore, the full-factorial analysis of variance revealed that for the tool with rε = 0.4 mm and 0.8 mm, the factors contributing the most to tool wear were cutting speed (38.76%) and cutting depth (86.43%), respectively. Originality/value: This study is of great significance for selection of cutting tools and cutting parameters for boring 1Cr17Ni2 martensitic stainless-steel parts. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0266/ [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the possibility of using mechanical spectroscopy to determine the strength of tool coatings from their lifespan. Mechanical spectroscopy with the determination of the index tan δ (internal friction) was used as the research method. Samples were coated with lamellae composed of WC-6wt% Co cemented carbides. The specimens measured 1.0 mm, 3.0 mm, and 40.0 mm, created using a conventional industrial liquid phase sintering procedure. The original powder consisted of cobalt with traces of chromium and vanadium, and submicron WC grains. The tools tested included carbide cutting tools, and the workpieces were steel alloys. Comparative results showed that coated tools had significantly improved tool life and durability. The relationship between the coating and tool life was evident, providing a practical approach for predictive and non-destructive analyses of coatings on tool durability for composite and finely structured materials. [ABSTRACT FROM AUTHOR]

Introduction: Friction drilling is an innovative method in hole-making for sheet metal applications, thin sheets of conventional structural alloy materials like copper, titanium, steel etc., even though there are other methods, such as thermal distortion for thewelding of nuts, riveting of nuts, and threading. For the last hundred years, researchers have focused on studying the development of this technique to maintain strength, hole roughness, hole geometry, hardness etc. It is interested in finding solutions for wear, tool life, and plastic deformation. Method: Friction drilling is also called a green hole-making process because this process uses the friction between the rotating tool and the workpiece. In this research, instead of regular HSS and Tungsten Carbide tools, the H13 tool steel is used, because the H13 steel tool has unique chemical compositions like chromium and molybdenum, which give high toughness, hot hardness, and wear resistance. Diamond-like-carbon (DLC) coating has been used in this research to enhance tool life and AZ31B magnesium alloy is used as the work material. Initially, in this research, the wear stability of the DLC-coated H13 tool was investigated, and later, the tool surface roughness and hole quality were verified. Results and Discussion: The material loss observed for the DLC-coated H13 steel tool in the pin-on-disk test was 0.05 g. This investigation used two different diameter tools, namely 3 and 7 mm. Research has concluded that the 7mmtool is better for friction drilling by seeing the roughness and hole quality. However, the conditions were that the spindle should rotate at 4,000 rpm and the feed rate of the tool to be at 200 mm/rev. [ABSTRACT FROM AUTHOR]

This work investigates the effects of high-current pulsed electron beam (HCPEB) irradiation on multi-layered TiN/TiCN/Al2O3 coatings deposited via chemical vapor deposition onto cemented carbide substrates. The study focuses on analyzing the impact of irradiation pulses on the phase composition, microstructure, mechanical properties, and cutting performance of these coatings. The results demonstrate that the multilayered TiN/TiCN/Al2O3 coatings exhibit a smooth surface with enhanced mechanical performance after HCPEB irradiation. Notably, the coating irradiated with 5 pulses achieves a maximum hardness of approximately 28.48 GPa, displaying improved wear resistance and cutting performance. These improvements can be primarily attributed to the enhancements in hardness and elastic modulus, along with the generation of residual compressive stress in the 5-pulse irradiated coating. [ABSTRACT FROM AUTHOR]

The erosion behaviors and mechanisms of low-carbon steel and alloy tool steel in several commonly used molten Al alloys were investigated via erosion testing. The erosion ratio of the low-carbon steel generally increased as the Si content of the melt increased and decreased as the Fe content of the melt increased. The erosion (dissolution) rate of low-carbon steel corresponded to the difference between the saturation solubility of Fe in the melt at the testing temperature (dependent on the Si content) and the Fe content of the melt via the same mechanism as that described by the Noyes–Whitney–Nernst equation. Conversely, the erosion rate of alloy tool steel (JIS SKD61) was almost constant, irrespective of melt composition. Moreover, the thickness of the semi-solid (diffusion) layer at the contact interface between the melt and alloy tool steel increased with the Si content of the melt. These trends are observed because the local increase in the apparent viscosity of the melt at the contact interface due to suspended carbide particles from the alloy tool steel negated the effects of the saturation solubility of Fe and the Fe content of the melt on the erosion rate. [ABSTRACT FROM AUTHOR]

Chip breakers are used in turning to improve chip breakage. In standard cutting inserts, they are pressed into the rake face before sintering. However, for specialized tools like profile grooving tools, this pressing is not possible. Instead, a laser preparation process can be applied after grinding the tool profile to create a diverse range of chip breaker geometries. The aim of this investigation is to gain insights into the relationship between the geometric parameters of laser-prepared chip breaker geometries and chip formation. For this reason, experimental turning investigations were conducted with varied chip breaker geometries. Based on these experiments, chip formation was observed for different profile geometries and chip breakers. The findings indicate that the inlet angle, outlet angle, width, depth, and lateral ridges significantly influence chip-breaking behaviour. These results can inform the development of application-specific design for chip breaker geometries. [ABSTRACT FROM AUTHOR]

The friction/adhesion between the tool and chip is generally large in metal cutting, and it causes many problems such as high cutting energy/rough surface finish. To suppress this, cutting fluid and tool coating are used in practice, but they are high in energy/cost and environmentally unfriendly. Therefore, this paper investigates the extraordinarily high-speed cutting (EHS cutting) mechanics of mainly soft and highly heat-conductive materials and proposes their application to solve the friction/adhesion problem in an environmentally friendly manner. In order to clarify the EHS cutting mechanics, a simple analytical model is constructed and experiments are conducted with measurement of the cutting temperature and forces. As a result, the following points are clarified/found: (1) heat softening at the secondary plastic deformation zone rather than the primary plastic deformation zone, (2) friction coefficient drop to 0.170 in EHS cutting, and (3) gradually increasing trend of cutting temperature in EHS cutting. Finally, EHS cutting is applied to dry cutting of aluminum alloys with a non-coated carbide tool and compared to conventional wet cutting with a DLC-coated carbide tool, and it is shown that a coating/coolant can be omitted in this region to achieve environmentally friendly cutting. [ABSTRACT FROM AUTHOR]

The performance of the final part of the turning process, a topic of practical importance, heavily depends on the cutting parameters. Surface quality, a crucial product attribute in manufacturing, often tops consumer demands during machining due to its significant influence on product functionality. This paper assesses the correlation between the detected vibration signal, statistical parameters (Crest, Kurtosis and I-kaz3D coefficient) and surface roughness and provides valuable insights for practical applications. When the tool experiences vibrations during material removal, these oscillations leave a ripple effect on the surface of the workpiece. We aim to determine the impact of cutting parameters on surface roughness while turning 42CrMo4 steel using a carbide tool insert. Cutting parameters, such as spindle speed, feed, and depth of cut, were used. Signal processing is carried out using different techniques to identify the effect of the cutting parameters on vibration signals. Finally, we delve into the interaction effects between the cutting parameters, vibration signals and surface roughness, offering a comprehensive understanding of real-world manufacturing scenarios. Higher I-kaz3D coefficients correspond to higher surface roughness values. The I-kaz3D coefficient decreases as the surface roughness measurements decrease, indicating that the I-kaz3D technique can accurately indicate an increase or decrease in surface roughness. On the other hand, the cutting force Fc was the component most strongly correlated with surface roughness (Ra), yielding the best results across all indices (adjusted R²adj = 95.1%, er=.8 ± 2.3%). [ABSTRACT FROM AUTHOR]

The hard part turning process used to finish the cylindrical surfaces has some critical machining responses like tool wear with the lower quality of the machined surfaces. Minimum quantity lubrication (MQL)-based machining environment is currently considered an advanced cooling and lubrication technique. Cutting speed, feed rate, and cutting depth are considered input parameters, and the TaguchiL27 orthogonal array (OA) has been adopted as the design of the experiment. In this context, average surface roughness (Ra), tool flank wear (VBc), cutting temperature (T∘C), and chip morphology have been selected as measured outputs. To improve the machining performance of hardened steel, a sustainable MQL (flank+rake directions) cooling system has been employed at the cutting zone. Iron–aluminum LRT 30 was considered as the base fluid for the hard turning of AISI 4340 steel by PVD (AlTiN) and CVD (TiN/TiCN/Al2O3) coating cutting inserts. The primary effects of process parameters and their influences on the measured outputs have been discussed. The dual jet MQL-based hard turning was performed at three levels of cutting speeds (80, 170, and 260m/min), feed rate (0.5, 0.1, and 0.15mm/rev), and cutting depth (0.2, 0.3, and 0.4mm) with an air pressure of 5bar and mist flow rate 50ml/h. The findings showed that PVD-coated carbide tools outperformed CVD-coated tools. The model of the measured outputs of both tools has been developed using second-order regression analysis. Utilizing ANOVA analysis, all the predictive models were observed to be significant and acceptable with larger than 90% of R2 value. [ABSTRACT FROM AUTHOR]

The present study focuses on the elimination of delamination during the drilling of a linen-based biocomposite material in epoxy resin used for the manufacture of sports kayaks, depending on the tool material, cutting conditions, and the use of additional wooden support plates. In the present study, HSS (high-speed steel) and Carbide cutting tools without coatings, with the same geometry and two types of cutting conditions (n = 1500 rpm, fn = 0.05 and 0.1 mm/rev) were used. A Sololite-type wooden backing plate was used to aid in reducing delamination. The results show that the additional support plates significantly reduced delamination by up to 80% both at the material inlet and especially at the drill hole outlet. In this study, the use of a lower feed rate (fn = 0.05 mm/rev) per tooth was shown to have a significant effect on reducing the delamination of biocomposite materials with flax fibers, which are generally known to be difficult to machine. The Carbide cutting tool shows significantly better results both in terms of its wear and in terms of delamination of the biocomposite material. The highest delamination was obtained without the use of a backing board at the tool exit after 50 drilled holes of 3509 µm. With the use of a backing board, this delamination decreased to 693 µm after 50 drilled holes. [ABSTRACT FROM AUTHOR]

This study describes the cutting performance of Monel 400 alloy using a cryo-treated AlTiN carbide tool. The AlTiN carbide tool was cryo-treated at −196°C for 24 h of soaking at a cooling rate of 0.5°C/min and then tempered at 200°C for 2 h at a heating rate of 0.5°C/min. In this work, we evaluate and compare the hardness, composition, and phases of untreated and cryo-treated AlTiN-coated carbide inserts and also the turning performance of Monel 400 alloy. The machinability characteristics of cutting temperature, turning force, roughness parameter (Ra), form of chip, and SEM-EDS analysis of turned inserts are evaluated and then compared. It was found that the cryo-treated (CT) inserts offered a higher hardness value by 1.5% than the untreated (UT) ones, due to the formation of a new hard surface coating with cryogenic treatment. Cryo-treated AlTiN coated carbide inserts provided the following benefits over untreated ones: lower the cutting temperature at the cutting zone by a maximum of 10%; decreased the cutting force by 6–14%; reduced the Ra values in the turned surface by a maximum of 83%; a reduction in the size of the serrated form of chip; a reduced rate of insert wear; and lower deposition of work material constituents in the turned insert. The reason is enhanced resistance to wear due to an increase in hardness and the formation of a new hard surface coating with cryo-treated AlTiN coated carbide inserts, which was confirmed by analyses of hardness, SEM coupled with EDS, and X-ray diffraction. From the comparison of the characterisation and machinability indices of untreated and cryo-treated AlTiN coated carbide inserts, it was found that the cryo-treated AlTiN-coated carbide inserts provided the favourable turning performance of Monel 400 alloy. [ABSTRACT FROM AUTHOR]

Surface roughness as a machinability index is very important parameter for getting a quality product in manufacturing industry because of affecting the fatique and fracture behaviour of any type of materials. Aim of the study is to generate statistical models in surface finish when machining AISI 1040 hardened mild steels with coated carbides including two different geometries of triangle and square under different conditions. The machining test was carried out at different cutting parameters of cutting speeds (65-76.5-90-104-119) m/min, feed rates (0.11-0.132-0.15-0.173-0.198) mm/rev. and depth of cuts (0.36-0.425-0.50-0.575-0.66) mm. The tools for experiment were coated carbide cutting tools that are formed by chemical vapour deposition while material used for the study was a mild steel, which is the generally used material for manufacturing industry. Furthermore, analysis of variance was used for determining the main factors/interactions. These results are compared and predicted through response surface methodology (RSM) and artificial neural network (ANN). Both approaches indicated that feed rate was dominant while others were not significant. Further, ANN's predicion ability was higher than RSM because coefficients of determination were equalled to 0.995 and 0.925 for ANN and RSM, respectively, which were associated with mean squared errors of 0.00056 and 0.0088 for ANN and RSM, respectively. Moreover, percentage errors for square-shaped inserts in randomly selected test was 6.66% and 1.50% for RSM and ANN, respectively. Hence, two models are good at predicting surface roughness, which in turn can provide a very valuable tool for design and manufacturing of engineering applications, but ANN spends less time and gives more accuracy. [ABSTRACT FROM AUTHOR]

Cemented carbide is a composite material of hard WC and soft Co, and has been widely used as a tool material because of its excellent balance of hardness and toughness. Among them, superfine cemented carbide with WC grain size of less than 1 μm is widely used as a base material for cutting tools and wear-resistant tools because it can achieve both high hardness and high strength. When using superfine cemented carbide as a cutting tool, it is essential to adopt the finer WC particles with higher Co dispersibility, in addition to the appropriate addition of grain growth inhibitors. If the WC particles can be finer, the hardness and transverse rupture strength of the alloy can be expected to improve. In addition, if Co particles, which are softer than WC particles, can be distributed more finely and homogeneously in the mixed powder, the mechanical properties of the alloy may be further improved. In this paper, we report on the improvement of Co dispersibility and the development of new ultra-fine WC, and introduce the cutting performance of the developed practical tools using above the WC powder. [ABSTRACT FROM AUTHOR]

This study was intended to investigate the mechanical property and cutting performance of AlTiBN coating for machining of exotic materials such as heat-resistant alloys and Titanium alloys, which has been increasing for aerospace, energy and medical industries. In conventional PVD coatings for cutting tools, Cr and Si has often been added to AlTiN in order to increase hardness and heat resistance, achieving high wear resistance. However, these methods increase hardness as well as Young's modulus, which reduces toughness of coating. In exotic materials milling, coatings with a high Young's modulus tends to develop internal cracks, leading to early destruction of the coatings. In this research, optimizing B content of AlTiBN coating, we realized low Young's modulus while maintaining high hardness. This is probably because the pure AlTiN changed to a mixed crystal structure of cubic and hexagonal by the addition of B. When the cutting performance of this AlTiBN coating was evaluated in milling for Inconel 718, it was found that internal cracks were suppressed at the initial stage of processing. As a result, cemented carbide tool with the AlTiBN coating achieved approximately 1.6 times longer tool life than that with B-free AlTiN coating. [ABSTRACT FROM AUTHOR]

The current work presents an approach for the optimization of machining parameters on the turning of Al7075-T6 aerospace alloy. The alloy was turned on a lathe machine equipped with four different metalworking fluid (MF) setups: minimum quantity lubrication (MQL), Ranque–Hilsch vortex tube (RHVT), compressed air, and dry cutting using coated carbide tools. Taguchi technique was considered for the design of the L16 experimental array with three variable factors and four levels, and S/N ratios were obtained. The turning parameters feed rate and cutting speed are optimized in the experiment, taking into account responses such as surface roughness and tool wear. ANOVA determined the significant parameters that majorly influenced the responses. The results demonstrated that the condition of machining (<99% probability) was the most influential parameter followed by cutting speed (<95% probability) which affects the surface roughness and tool wear. Moreover, turning with MQL at a low cutting speed represented the optimum machining setup for reducing surface roughness and tool wear of this alloy. It was due to the fact that MQL decreases the friction between the tool and the workpiece which reduce the mechanical and thermal stresses on the cutting tool, resulting in lessened tool flank wear and effectively improving the surface quality. [ABSTRACT FROM AUTHOR]

The Ti-5Al-5V-5Mo-3Cr alloy is utilized in the aerospace, biomedical, and military industries for its exceptional thermomechanical properties. However, its comparatively higher strength and toughness render it more difficult-to-cut than traditionally employed Ti alloys such as Ti-64. Despite its growing demand, a noticeable gap concerning the finish turning of Ti-5553 using coated carbide tools was identified. This paper aims to address this gap by conducting a comprehensive investigation of the tool life and micromechanical performance of novel mono/bi-layered PVD-coated WC tools under high-speed finish turning and wet conditions. A commercial AlTiN-based coating serves as the baseline reference layer and was compared with mono-layered ta-C (diamond-like carbon, DLC), AlCrN, and TiAlSiN coatings deposited atop the AlTiN base on three separate cutting tools. The study focused on evaluating the tool life and surface finish results of all the coatings. Demonstrating that the AlTiN/AlCrN coated tool exhibited the longest tool life, improvement of ~ 9.02% with reference to the baseline, while imparting the smoothest surface finish, an improvement of ~ 31.81%, on the workpiece material due to its optimal micromechanical properties and conducive oxide formation. The results obtained offer valuable insight into understanding the relationship between machining performance and coating properties, consequently allowing the industrial sector to refine its selection criteria to aid with productivity and quality assurance. [ABSTRACT FROM AUTHOR]

Axial ultrasonic vibration-assisted micro-milling (UVAM) has emerged as an advanced technique that can be tailored to improve the machinability of difficult-to-machine materials such as 316L stainless steel. This article sets out to meticulously compare and analyze the cutting performance of conventional milling (CM) and UVAM techniques in the side milling of 316L stainless steel. The cutting separation characteristics of UVAM of 316L stainless steel are elucidated, and the air-cutting ratio in UVAM is introduced. The relationship between the air cutting ratio and spindle speed is also derived. Based on theory, the finite element simulation and experiments are compared under both milling conditions. An analysis of the results for these two sections is presented to validate the theoretical derivation. The results show that the trend and analysis of the experimental cutting forces are aligned with those in the simulation. The cutting forces also confirm the reliability of the simulation results. Due to factors such as tool wear, there is a deviation of 5–20% between the experimental values and the simulation results. A chip variation analysis in the simulation also corresponds to the trend in cutting temperature. An evaluation of the surface morphology and roughness of the experimental samples reveals that the surface quality and smoothness under UVAM are superior to those under CM. Tool wear analysis indicates that the carbide tool undergoes severe wear in the side milling of 316L stainless steel. In summary, the simulation and experiments convincingly demonstrate the advantages of UVAM technology and provide a reference for optimizing the milling process of challenging materials. [ABSTRACT FROM AUTHOR]

Milling difficult-to-machine metals like titanium alloys requires a precise surface finish at the nanoscale levels. This examines the surface properties of the Ti-6Al-4V alloy when milled in a tungsten carbide tool coated with TiAlN. With the latest technological improvements, more awareness is being developed to utilize the field of Machine learning. This research is focused on different Machine learning algorithms such as Neural networks (NN), Linear Regression analysis (LR), and Hyperplane based Support Vector Regression (SVR) are being employed to predict the accuracy of the cutting force and Surface finish (Ra) model during milling of Titanium alloy machining. The cutting force is simulated using the AdvantEdge software and compared the results with experimental values using a PVD-coated cemented tungsten carbide tool coated with TiAlN. Taguchi analysis was applied to the milling process in dry conditions using various cutting speeds (120-180 m/min), feed rates (0.05-0.1 mm/tooth), and depths of cut (0.5-1 mm) while applying TOPSIS multi-criterion decision making to get the optimum process parameters for cutting forces. According to the TOPSIS multi-criterion technique, cutting speed has the biggest contribution (64.17%) when compared to the feed rate (18.12 %). Milling cutting force is analyzed using the Deep learning model and compared the results with experiments and error percentile are calculated to obtain the most optimum model for the prediction. The productivity of the manufacturing product is improved by using simulation software to predict the cutting force and surface roughness and implementing intelligent machine learning tools. The polynomial regression model was used to predict the cutting force on milling Ti alloy and found that linear regression prediction was 220.21 whereas polynomial regression prediction was 222.98 at depth of cut 0.5 mm which is more accurate and the curve is fitted properly with most of the data points. [ABSTRACT FROM AUTHOR]

In modern industrial production, noise can reflect the cutting state of the workpiece and tool to a certain extent, and the noise collection method cannot interfere with the complex processing environment. To further improve the cutting performance of coated cemented carbide micro-textured tools, this paper builds a friction and wear test platform for micro-textured cemented carbide pins with AlSiTiN-AlCrN coating and titanium alloy discs. Based on the test noise signal, the relationship between friction and wear and the noise of the workpiece was studied by the Hilbert–Huang transform (HHT). Through the change of noise in different periods, the micro-texture and coating life of cemented carbide pin under other processing parameters were analyzed. Based on the influence of the interaction between processing parameters and micro-texture diameter on the test results, the test parameters were optimized. The results show that the change of noise signal during the test presents a "V" curve with the grinding process, which mainly affects the noise through the shift of pin-disc friction form and the anti-wear effect of micro-texture. The interaction mainly affects the test results by affecting the micro-texture diameter, laser energy concentration, and the roughness of the inner wall of the pit. The optimized micro-texture geometry and preparation parameters are as follows: scanning times is 8, micro-texture diameter is 50 μm, scanning speed is 1500 mm/s, micro-texture spacing is 170 μm, and laser power is 40 W. The research content of this paper provides a reference for improving the surface properties of cemented carbide. [ABSTRACT FROM AUTHOR]

A good understanding of the interplay between the cutting tool edge radius, elastic recovery, friction, and contact pressure is essential for better modeling of ploughing forces during micro-scale cutting. This study conducts plunging tests on an ultra-precision CNC with engineered tungsten carbide cutting tools on commercially pure titanium alloy. The cutting tool edge radius is prepared to be around 3.5–4 μm, which resembles those cutting tools used in micro scale machining. During plunging tests, the micro cutting tool is given a sinusoidal movement with an amplitude close to edge radius of the tool as the work material is rotated at a constant speed. The residual depth profiles of the webs corresponding to the commanded depths were investigated in detail to identify elastic recovery rate. The cutting and thrust force measurements during plunging experiments together with identified elastic recovery rate was employed in an analytical model of micro scale machining to obtain the variations of contact pressure and coefficient of friction as a function of commanded depth. Due to the scale of the experiments that were performed, the effects of surface topography of the cutting tool and possible alignment errors are also considered in the analytical model. A linear relationship between the contact pressure and elastic recovery has been identified during ploughing-dominated machining conditions for the work material and the cutting tool pair considered in this study. The proposed experimental technique is shown to be promising in terms of modeling ploughing forces during micro-scale cutting. • Plunging tests reveal the influence of edge radius on elastic recovery. • A linear relationship between contact pressure and elastic recovery. • Coefficient of friction remains almost constant during ploughing. [ABSTRACT FROM AUTHOR]

Tool wear is a key issue for the manufacturing performance of refill friction stir spot welding in high-volume manufacturing environments. As such, the aim of this study is to examine conditions in which tungsten carbide with a cobalt binder can succeed as a tool material in the spot welding of 2029 aluminum for a sustained lifetime. Critical factors are shown herein to include cleanliness and thermal management. The life of a WC-Co toolset is demonstrated to be approximately 2998 welds, which is of the same scale as conventional steel tooling. With a WC-Co shoulder and probe, the H13 clamp showed the only significant wear. [ABSTRACT FROM AUTHOR]

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The surface roughness and surface residual stresses are affected by the coating thickness of physical vapor deposition (PVD) TiAlN tools, which could alter the service performance of machined components. However, the relationships among the tool coating thickness, the machined surface roughness, the surface residual stress, and the fatigue life are still not sufficiently illustrated. In this research, PVD TiAlN coatings with several thicknesses of 1.6 μm, 2 μm, 2.5 μm, and 3 μm were deposited on carbide tools. Turning experiments using Inconel 718 were conducted with uncoated and various TiAlN tools under flood cooling conditions. The surface roughness could be improved with the selection of thin PVD TiAlN coating thicknesses of 1.6 μm and 2 μm compared to that of uncoated tools. The tensile residual stresses at the machined surface in the directions of cutting speed and feed rate linearly decreased by 148.67% and exponentially decreased by 92.24% when the TiAlN coating thickness was increased from 0 μm to 3 μm. The values of the low-cycle fatigue life of machined Inconel 718 linearly increased by 15.60% with the increase in TiAlN coating thickness from 0 μm to 3 μm, which was mainly due to the improvement of surface residual stresses. The results could provide guidance for the selection of suitable TiAlN coating thicknesses for wet machining Inconel 718 based on the part service conditions. [ABSTRACT FROM AUTHOR]

Vanadis 8 steel is a tool steel manufactured by powder metallurgic processing. Its main alloy elements are V, Cr and Mo. By implementing an experimental design with five factors—all of them are related to the thermal processing of this steel and with ionic nitriding—the effects of said factors on adhesive wear resistance and corrosion resistance were studied. For this purpose, Pin-on-Disc wear tests and lineal polarization resistance tests were carried out using an aqueous solution with 3.5% NaCl by weight. The main aim was to increase this steel use in more aggressive environmental conditions, such as in coastal environments. By means of XRD, the percentage of retained austenite was determined, and by SEM-EDX, the microstructure was revealed. The conclusion is that adhesive wear resistance is improved if thermal processing parameters are at such levels that increase austenite destabilization and reduce retained austenite content. This means to destabilize austenite at 1180 °C during 1 h, with oil quenching, tempering at 520 °C during 2 h and ionic nitriding at 520 °C during 2 h. Corrosion resistance is highly improved with ionic nitriding. At the same time, to compensate for the negative effect on corrosion resistance of a high density of primary and secondary carbides, it is essential to carry out the ionic nitriding treatment. The harmful effect of electrochemical microcells that appear in the carbide/matrix interface is compensated by the passivating effect generated by the nitrided surface. [ABSTRACT FROM AUTHOR]

It is currently known that in certain circumstances pre-rounding of cutting blades can significantly increase tool life. Despite many data on the beneficial effect of drag-finishing on the durability of metalworking tools, it is not entirely clear whether similar benefits appear when machining wood-based panels. The results of some pilot study are quite promising but the real impact of cutting blades pre-rounding (it is about blades made of various standard cemented carbides), on tool life in particleboard milling are very rarely studied. The study aims to fill this gap in the knowledge system. The experimental research was carried out using a CNC milling machine equipped with a single-blade milling head with replaceable blades. It turned out that the positive effect of the drag-finishing of cutting blades on tool life in particleboard machining depends on the structure and hardness of carbide. A significant extension of the tool life (about 50%) was observed only in the case of particularly hard carbide (2240 HV10). There was no significant advantage for the softer type of carbide (1800 HV10). [ABSTRACT FROM AUTHOR]

The tool wear characteristics and mechanisms were investigated during interrupted-cutting Zr-based bulk metallic glass (BMG). The effect of tool wear on the cutting forces, chip morphology, and machined surface quality was also analyzed. The increase in cutting speed significantly affected the transformation of tool wear behavior. The cutting tool failure form was mainly characterized with adhesive wear and edge chipping. The enhancement of cyclic mechanical impact, caused by the increase of cutting speed in interrupted-cutting, was the main reason for the tool wear behavior transition and life reduction. Furthermore, oxidation wear led to serious boundary wear. The tool wear drastically altered the chip morphology, and the free surface serrated feature disappeared, which was replaced by flaky droplets with the increase of cutting speed. Moreover, it also led to various surface defects on the machined surface, among which the plastic side flow showed the most significant impact on surface roughness. [ABSTRACT FROM AUTHOR]

Inconel 657, also known as 50Cr-50Ni, is a high-temp, corrosion-resistant Ni-Cr alloy with excellent fuel-ash corrosion resistance against sulfur and vanadium. To make components from Inconel 657, it undergoes casting and machining for dimensional accuracy and surface finish. This study explores the effect of cutting speed on tool wear in turning Inconel 657, focusing on carbide and CBN tools. Higher cutting speeds led to increased flank wear for both tools. Carbide tool wear rose by 16% and 25% at 60 and 120 m/min compared to 30 m/min. CBN tool wear increased by 15%, 29%, and 66% at 120, 250, and 400 m/min compared to 60 m/min. CBN inserts showed 39% less wear than the carbide tool at 60 m/min and 35% less at 120 m/min. Therefore, the carbide tool suits low-speed turning, while the CBN tool is ideal for high-speed machining operations. [ABSTRACT FROM AUTHOR]

This study examines the process of optimising machining parameters in the turning of EN8 steel. The PROMETHEE-II multicriteria decision-making technique is utilised for this purpose. The analysed machining variables consist of Material Removal Rate (MRR), Surface Roughness (SR), Acceleration (Ac), and Tool Wear (TW). These variables are influenced by the cutting speed (Vc), Feed Rate (FR), and Depth of Cut (DoC) which serve as input parameters. The experimental trials were performed utilizing Taguchi's L27 orthogonal array on a CNC lathe. The ANOVA analysis showed that Vc had the most substantial effect on MRR, SR, and Ac, whereas FR had the greatest influence on TW. The PROMETHEE-II approach determined that the most favourable machining settings are a cutting speed (Vc) of 200 m/min, an FR of 0.08 mm/rev, and a DoC of 0.2 mm. Given these circumstances, the MRR achieved a value of 2.887 cubic millimetres per second, the SR was minimized to 0.744 micrometres, the Ac was decreased to 0.026 meters per second squared, and the TW was restricted to 0.026 millimetres. The study finds that PROMETHEE-II is a highly successful method for optimizing multiple machining reactions, resulting in substantial enhancements in machining performance. [ABSTRACT FROM AUTHOR]

With stricter emissions regulations and higher engine performance demands, the high-quality processing of Compacted graphite cast iron (CGI) for the automotive industry has received more and more attention. Coated carbide tools are now widely used to cut CGI. The coating material is an essential factor affecting processing efficiency and cost. However, the processing adaptability and wear mechanism of tool coating materials to CGI has yet to be thoroughly studied. CGI milling experiments in this paper were carried out using different coated carbide tools. The effect of coating materials on milling forces, tool wear and surface roughness for coated tools under different cutting parameters were compared and evaluated. It is found that TiAlN/TiN coated tools have the best cutting force, tool wear, and surface roughness, followed by TiAlN/AlCrN coated tools. The analysis of the tool failure process shows that bonding and oxidation are the main wear mechanisms of TiAlN/TiN, TiAlN/AlCrN, and TiCN coated tools, while bonding is the primary wear mechanism of TiN/TiCN/Al2O3 and TiN/MT-TiCN/Al2O3 coated tools. The wear mechanism of the flank is groove and coating wear, and the wear process is removing the coating material on the tool surface and chipping the unprotected cutting edge. When comparing the tool durability, it was found that the tool life of TiAlN/TiN was extended by 17.4 %–28.6 % (v = 150 m/min, f = 0.1 mm/z, ap = 0.4 mm) and 5.3 %–17.6 % (v = 250 m/min, f = 0.2 mm/z, ap = 1 mm), respectively, compared to the rest of the coated tools. Based on the average surface roughness (Ra) values obtained for the same cutting distance, TiAlN/TiN performed better than the rest of the coated tools by 8.1 %–40.1 % (v = 250 m/min, f = 0.1 mm/z, ap = 0.5 mm). In addition, the study of the machined surface roughness shows that the surface roughness is affected by the flank wear width and the cutting fluctuation caused by it. [ABSTRACT FROM AUTHOR]

During the machining of aluminum alloys, the adhesion of chips to the tool affects the performance characteristics. Today, different cooling systems are used to eliminate these negativities. In this study, the effects of end milling using HSS and carbide cutting tools of 6061-T6 aluminum alloy on surface roughness, chip thickness ratio and tool wear were examined using different cooling techniques (dry, minimum quantity lubrication (MQL) and nanocutting fluid). Different cutting speeds (180, 200, 220 m/min) and different feed rates (0.05, 0.06, 0.07 mm/rev) were used in the experiments. According to experimental findings, tool wear and surface roughness decreased at low cutting speed and feed rate by using nanocutting fluid with carbide cutting tools. It has been observed that the chip thickness ratio increases with high cutting speeds using nanocutting fluid and decreases with dry machining and high feed rates. The best milling performance of the aluminum alloy was achieved in experiments using carbide cutting tools and nanocutting fluid. [ABSTRACT FROM AUTHOR]

In machining, tool temperatures and thus tool wear are significantly influenced by frictional behaviour. Friction tests are used to determine the friction coefficient depending on relative speed, which serves as basis for parameterising friction models as input data for chip formation simulations. Therefore, this paper represents investigations towards the frictional behaviour of uncoated and coated (TiN, TiAlN) carbide tools when using two different relative movements (translational and rotary) and cooling lubricant conditions. In dry conditions, the investigations show insignificant influence of different engagement surfaces and testing kinematics on resulting friction. In lubricated conditions, three different friction coefficient sections were observed. [Display omitted] [ABSTRACT FROM AUTHOR]

Using a duplex deposition of TiO2/8YSZ on a carbide cutting tool, a successful sol-gel procedure was achieved, resulting in high homogeneity, good dispersion, and a low average value of surface roughness (223.6 nm). Thermal experiments were done to see how well the coating layers could withstand heat transfer and thermal deterioration. Residual stresses for coated and uncoated carbide cutting tools are measured after thermal shock (thermal shock). Both were immediately chilled in ice water after being heated for 90 minutes for coated inserts and 30 minutes for uncoated inserts at 500, 600, 700, 800, 900, and 1200 °C. For inserts, thermal shock from 900 °C results in significantly different damage mechanisms. The uncoated outside surface is still delineated by a crack network and is surrounded by nearby homogenous cells, but the coated insert (sol-gel TBC) in this case really has a few tiny cracks beginning at the edge. The coated insert fails after being heated to 1200 °C and then cooled in water to freezing which is caused the start of the duplex coating degradation. [ABSTRACT FROM AUTHOR]

In the present study, Experimental investigation of the effects of various cutting parameters on the response parameters so as cutting zone temperature (T) and material removal rate (MRR) in the turning of EN AW 1350 Aluminum Alloy by coated carbide tool. The input control parameters selected for the present work were the cutting speed, feed rate and depth of cut. The objective of the present work is to examine the cutting zone temperature and material removal rate for better productivity. The design of experiments was done with the help of Taguchi L27 orthogonal array. Analysis of variance (ANOVA) was used to find out the significance of the input parameters on the response parameters. Percentage contribution for each control parameter was calculated using ANOVA with 95 % confidence interval. From results, it was observed that cutting speed is the most dominant factor for temperature and the depth of cut is the most significant control parameter for material removal rate. Finally, the multiple response optimization of cutting zone temperature and material removal rate was carried out using the desirability function approach. [ABSTRACT FROM AUTHOR]

To curtail the negative effects of traditional flood machining, dry cutting using carbide tools has emerged as a prominent alternative for manufacturers, owing to its low cost and phenomenal surface qualities. In line with this view, high-speed machining of high-strength AISI 4340 alloy steel was carried out using multilayer Al2O3/TiCN-CVD and TiAlN/AlCrN-PVD carbide tools in a dry environment. The experimental scheme was adopted, as per Taguchi's L18 orthogonal array, to investigate the two most crucial machinability aspects, namely tool life and surface roughness. An analysis of variance (ANOVA) was performed on the obtained data, and it was inferred that the feed rate exhibited the strongest effects on both the tool life and surface roughness, with corresponding percentage contributions of 46.22% and 68.96%, respectively. The longest tool lives of 14.75 min and 10.08 min were obtained at a low cutting speed and feed rate for CVD and PVD tools, respectively. However, the lowest surface roughness of 0.276 µm and 0.307 µm was achieved at a high cutting speed and low feed rate for PVD and CVD tools, respectively. The evolution of tool wear, studied through the microscopic images of the worn tools, revealed that a high cutting speed and feed rate accelerated the flank wear for both types of tools. Nevertheless, the CVD tool exhibited better results due to the thick and effective Al2O3/TiCN coating layer, which protected the carbide substrate against thermal–mechanical loads. Moreover, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) performed on the worn tools revealed that adhesion, oxidation, diffusion, and abrasion were the main wear mechanisms for both types of tools. [ABSTRACT FROM AUTHOR]

Cutting tool sintering process is one of the key links in cutting tool manufacturing process. Various physical quantities change with time during cutting tool sintering. As the sintering quality of cutting tool is directly affected by these changes, it is very difficult to predict and control the sintering quality of cutting tool. Due to the complex structure of sintering equipment, it is difficult to obtain high quality and sufficient data to train the sintering quality prediction model. In this paper, the real-time condition monitoring, prediction and control of carbide cutting tool during sintering process are studied. In this study, a digital-twin model of cemented carbide cutting tool sintering furnace was established. Based on this model, the change of heat distribution characteristics in sintering furnace during sintering process is precisely described. Firstly, the paper establishes the mapping architecture of cutting tool sintering digital-twin system. Based on this architecture, a digital-twin model of heat radiation in sintering furnace is established in this paper. Based on the temperature and pressure data in the sintering furnace, the radiation heat transfer in the furnace is analyzed in order to determine the temperature change of the cutting tool sintering position. In this paper, the relationship between the temperature change of cutting tool sintering position and cutting tool grain size is studied. Based on this relationship, a rolling data-driven digital-twin prediction model for cutting tool sintering has been constructed. In this paper, cutting tool sintering temperature control driven by digital-twin system is realized based on a fuzzy control model. The validity of the digital-twin system is verified by a series of comparative experiments. The test results show that the temperature error of the system control is less than ±1 °C. It effectively improves the qualified rate of cutting tool sintering. [ABSTRACT FROM AUTHOR]

The current study sought to determine the influence of strontium addition on the microstructure and machinability of the A357 alloy. Furthermore, the influence of cutting parameters and aging temperatures on the machining performance of the modified alloy was investigated using a statistical technique. The machinability characteristics were investigated by milling experiments with a carbide tool. Experimental trials were carried out using Taguchi's L27 orthogonal array. Process parameters studied were strontium (Sr) percentage, aging temperature, cutting speed, and feed rate. Cutting force, surface roughness, and tool wear were investigated as responses. The microstructure of the specimens revealed that the addition of Sr to the A357 alloy helped to achieve refined grain structure. Furthermore, increasing the Sr concentration from 4 to 8% resulted in the enhanced refined microstructure. ANOVA analysis of responses revealed that Sr%, aging temperature, and feed rate have a significant effect on all the responses considered. However, cutting speed has exhibited the least influence. Further, the increase in Sr% resulted in an increase in cutting force and tool wear. Whereas, a decrease in surface roughness was observed due to increased Sr%. Whereas the increase of aging temperature, cutting temperature, and feed rate has resulted in the increase of response values. The aging temperature has shown significant influence on the variation of cutting force and surface roughness.. [ABSTRACT FROM AUTHOR]

High strength low alloy (HSLA) AISI grade 4140 is grabbing the eyes of automobile industries for its superior properties. However, the production of finished components of HSLA steel by machining under dry environment is challenging owing to high cutting temperature and friction. The usage of low-cost coated carbide tools and environment-friendly cooling-lubrication approach are thereof being given importance for the past few decades for economic and sustainable machining. In this study, the power consumption (Pc) during the hard turning process of AISI 4140 steel was analyzed using an AlTiSiN-coated carbide tool under various cutting environment conditions, including dry cutting, flooded cutting, and nanofluid-MQL cutting. For this study, the nanofluid was prepared by blending MWCNT nanoparticles with an environmentally friendly automotive radiator coolant, which served as the base fluid. Briefly, the cooling-lubrication performance is investigated by comparing the machining responses like machined surface morphology, tool wear, cutting force, and temperature. The variance analysis was adopted to determine the significance level of experimental parameters (speed, feed, nose radius, depth of cut, cutting environments) affecting the Pc. To predict and optimize Pc during hard turning with machining variables, the response surface method (RSM) was proposed. Following the predictive modeling and optimization, the results were applied for economic assessment and for energy saving carbon footprint evaluation. This innovative research also addresses comparative sustainability evaluation in hard turning under different C/L environments using life cycle assessment (LCA) towards cleaner and safer production. Results indicate that cutting speed was the most influential item on Pc enhancement. Furthermore, as compared to dry and flooded turning, lower cutting force, reduced cutting temperature, shorter width of flank wear, and better surface morphology are obtained under nanofluid-MQL machining. It is experienced that nanofluid-MQL machining outperformed towards sustainability improvement concerning techno-economically viable societal acceptable and environment friendliness. [ABSTRACT FROM AUTHOR]

This research studies the energy consumption and wear mechanism of carbide cutting tools in dry machining of Ti6Al4V alloy. In the first phase of experiments, full factorial design experiments were employed to study the tool wear rate (R) and specific cutting energy (SCE) with respect to the machining conditions (cutting speed and feed rate). Results showed that machining responses such as tool wear and energy consumption are affected by cutting conditions, thus requiring investigation to understand the wear mechanisms. Therefore, in the second phase, additional experiments were performed to investigate the tool-workpiece interactions at the cutting conditions reported to have low, moderate, and high tool wear. It was revealed that strong adhesion and material transfer between the tool and workpiece caused high wear. Electron dispersive X-ray spectroscopy (EDX) analysis of worn tools showed that the transfer of tungsten (W) and cobalt (Co) to the workpiece and titanium to the tool surface is the primary cause of tool deterioration. As a result, diffusion and dissolution have degraded cutting performance and weakened the tool edge, leading to rapid wear. Furthermore, worn tools resulted in relatively higher energy consumption per unit volume of material removed at the tooltip. The degradation of cutting performance and weakening of the tool edge results in rapid wear and higher energy consumption. The study suggests that minimizing tool wear is crucial for energy reduction, improved sustainability, and cleaner production goals in dry machining of titanium-based alloys. [ABSTRACT FROM AUTHOR]

The motive of present work is to explore the variation in the material characteristics of steel upon multi-pass friction stir processing. Steel plates (IS2062) that were 3 mm thick, were subjected to friction stir processing in a multi-pass manner. The selected transverse speed was 150 mm/min, along with a tool rotation of 800 RPM when using a tungsten carbide tool (shoulder diameter—10 mm). Steel plates were processed using the single-pass, double-pass, and triple-pass travel of the rotating tool to observe the impact of multi-pass processing on the properties of steel plates. Multi-pass friction stir processing resulted in a higher micro-hardness of 175 VHN after the second pass, in comparison to the unprocessed metal, which had a micro-hardness of 130 VHN, owing to the collective effect of the plastic flow of the material due to the rotation of the tool and frictional heat, which also leads to grain refinement. The second pass evidenced an average grain size of 22 microns, whereas the unprocessed material had an average grain size of 57 microns. The results of EBSD and SEM characterization showed reasonably improved material properties of the processed work materials. [ABSTRACT FROM AUTHOR]

304 stainless steel demonstrates a low thermal conductivity and work hardening characteristics, resulting in its processing, and will adhere to the tip of the tool; as well as the phenomenon of chipping, shortening the life of the tool. AlTiN coatings are representative of coatings applied to carbide tools. In this paper, AlTiN coatings with different arc current processes were deposited on carbide milling inserts using arc ion plating. The microstructure, mechanical properties, and milling properties of the coatings were investigated by using the SEM, EDS, XRD, scratch meter, friction and wear meter, and vertical machining center. The findings revealed that all coatings displayed columnar crystal growth, free from cracks and voids. With an increasing arc current, there was a notable increase in surface droplets, pits, and coating thickness. The coating deposited at a 140 A arc current showed a pronounced (200) orientation preference. The adhesion force peaked at 56.0 N with a subsequent decline, and the friction coefficient hit its lowest point of 0.429 at 140 A, contrasting with its highest value of 0.55 at 160 A. After 39 min of dry milling, the tool with a 140 A AlTiN coating exhibited minimal wear of 0.196 mm, just below the 0.2 mm failure threshold, indicating superior performance at this arc current setting. [ABSTRACT FROM AUTHOR]

An experimental investigation was performed using a tungsten carbide tool to study the micro-electrical discharge machining behavior of two different grades of stainless steel (310 and 316 SS). The machining parameters considered to investigate the machining behavior of the chosen materials were (a) V: voltage (V), (b) C: capacitance (pf), (c) Ton: pulse-on time (µs), and (d) Toff: pulse-off time (µs). The machining behavior of stainless steel was evaluated in terms of material removal rate and tool wear rate. Taguchi L16 orthogonal array and gray relational analysis techniques were employed to design and optimize the machining conditions for both responses. Scanning electron microscopy, energy-dispersive spectroscopy, and optical microscopic analyses were also performed to identify the characteristics of the machined surface, characteristics of the micro-tool, and the elemental composition of the machined surface. The optimum machining condition for 310 steel was found as 150 V, 100 pf, 30 µs (Ton), and 20 µs (Toff). On the other hand, the optimum parametric condition for 316 steel was 200 V, 1000 pf, 20 µs (Ton), and 25 µs (Toff). [ABSTRACT FROM AUTHOR]

The pursuit of precision machining in engineering materials has ignited an imperative to advance electrical discharge machining (EDM) techniques. This study is a deep dive into the domain of micro-electrical discharge machining (μ EDM) with a specific focus on the utilization of carbon-coated tool electrodes. The primary objective is to elucidate the influence of carbon-coated electrodes on vital machining parameters, including machining depth (Z coordinate), tool wear rate (TWR) and overcut (OC) in μ EDM operations. Moreover, the investigation extends to scrutinizing surface characteristics generated by μ EDM with carbon-coated tool electrodes. To enhance performance, carbon-coated tungsten carbide tool electrodes are employed for machining titanium alloy (Ti–6Al–4V) workpieces. The optimization process seeks to identify the optimal combination of process parameters using a Taguchi-DEAR-based multi-response approach. Experimental findings reveal that integrating carbon-coated electrodes significantly improves the μ EDM process, leading to enhanced surface performance metrics. Notably, this study identifies specific parameter settings that effectively optimize machining quality indicators. By achieving a voltage of 160 V, a capacitance of 10,000 pF and a tool rotation of 600 RPM, the research contributes valuable insights into the intricate realm of μ EDM, highlighting the potential for enhanced surface performance through strategic parameter manipulation. [ABSTRACT FROM AUTHOR]

Limited research work has been performed to investigate the effect of biological structures and their position (rake surface, flank surface) on cutting tools in enhancing cutting performances. Therefore in current work, effect of change in position of different conventional structures (micro-dimples, micro-grooves) and bio-inspired micro-crescent geometrical structures on machining characteristics of hard-to-cut martensitic AISI 420 steel has been investigated. The structures were generated on a carbide tool using laser machining. The dry turning operation was conducted at constant feed (fz) = 0.14 mm/rev, speed (vc) = 315 m/min, depth (ap) = 0.20 mm. From the obtained responses, it is noticed that the bio-inspired flank surface and rake surface crescent structured tool outperformed other structured and conventional tools. It happened because structures on rake and flank surface of tool helped in enhancing machining performance by breaking contact between interface of the chip–tool, acting as an entrapper of wear debris particles and improving heat transfer between tool–workpiece interfaces. The bio-inspired structured tool also showed minimum tensile residual stress of 315.6 and 390.2 MPa in feed and cutting direction on the machined surface. The results indicate a reduction of 56.44, 28.91, 19.04 and 19.02% in the flank wear, feed force, tangential force and average surface roughness using crescent-shaped rake and flank-faced tool relative to the conventional tool. The research results are very important for expanding the applications of bio-inspired structured tools in various machining operations. [ABSTRACT FROM AUTHOR]