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The conventional cutting fluid which is mineral oil-based has been used in numerous cutting operations which require the removal of materials. The negative effect of mineral-based oil is of great concern. This includes skin irritation and respiratory problems for machine operators, and contamination of soil and water when poorly discharged into the environment. A viable alternative must be developed which will be human and environmentally friendly. The introduction of vegetable oil can be a good alternative. Moreover, this will give room for the mixture which will result in obtaining oil that will be performed efficiently in machining and be environmentally friendly. Oils for these operations can be extracted from non-edible vegetable seeds that are deemed unfit for human consumption and refined into metalworking oil for machining. Because the demand for vegetable oils for food has risen in recent years, it is no longer viable to justify their use in machining. As a result, the current research focuses on the use of non-edible oilseeds for machining. African star oil was used as a coolant in the machining of 6061 aluminum alloy at various spindle speeds, feed rates, and cut depths. Parameters such as surface roughness and cutting temperature were measured in the evaluation for the developed African star oil, mineral oil, and dry machining environments. African star oil has demonstrated by its functionality that it can machine AA6061 with the same efficiency as a conventional cutting fluid and much better than dry machining. African star oil as cutting fluid improved surface quality and demonstrated efficient cooling behavior at the workpiece-tool interface. [ABSTRACT FROM AUTHOR]

Efficient lubrication and cooling are crucial in machining operations to enhance tool life and workpiece quality. Sustainable methods like minimum quantity lubrication (MQL) and dry cutting often face limitations in cooling efficiency and chip evacuation, especially under high-speed conditions or when machining difficult-to-cut materials such as stainless steel. This study introduces the novel pressurized injection lubrication (PIL) technique designed to address these challenges by optimizing lubrication, cooling, and chip evacuation during the turning operations of stainless steel 304. Using flaxseed oil as the lubricant, the PIL system employs a 0.26 mm stream diameter at a pressure of 16 bar to provide the necessary cooling and lubrication to the cutting zone. Cutting temperature and surface roughness were selected as the primary responses. Experimental runs were designed using the Taguchi L9 method. Analysis of variance showed that the lubrication method significantly affected the cutting temperature, with a contribution percentage approaching 94%. The experimental results demonstrated that PIL reduced the cutting temperature by up to 55%, while MQL reduced it by about 48%, both compared to dry cutting at the highest utilized speed. The lubrication method was also found to be the most significant factor affecting surface roughness, with a contribution percentage of 72.8%. Experimentally, PIL improved surface roughness by a maximum of 16.2% compared to MQL. Additionally, PIL maintained low oil consumption (0.9 l/h) and energy usage (< 0.017 kWh). The cost-effective PIL setup, priced under 65 USD, underscores its potential as a sustainable and efficient alternative for machining processes. The system's components are readily available, facilitating easy integration into existing metal-cutting machines. Finite element analysis (FEA) modeling was used to predict residual stresses under different lubrication methods. The FEA model indicated that PIL and MQL reduced residual stresses by about 81.2% and 76.6%, respectively, compared to dry cutting at a speed of 500 rpm. These findings suggest that PIL can significantly enhance machining performance and sustainability, offering a viable solution to modern manufacturing challenges. [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 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]

High-speed milling (HSM) of Ti-6Al-4V is subjected to complex thermo-mechanical loads, leading to alteration in metallurgical conditions within the cutting deformation zones, adversely impacting the mechanical performances of manufactured products. Hence, inclusive insight into microstructural alterations within the Adiabatic Shear Band (ASB) and the milled surface becomes essential for better service performance. This study first developed a Finite Element (FE) milling model to simulate the machining process of Ti-6Al-4V. The proposed FE model is validated through experimental results regarding cutting forces (CFs), cutting temperature (CT), and chip geometry, where the absolute relative error between simulations and experiments was less than 15 %. Secondly, Zenner-Holloman (Z-H) and Hall-Petch (H-P) equations were incorporated into a user-defined subroutine to simulate dynamic recrystallization (DRX) for grain size and microhardness prediction. Simulation results revealed that the grains became finer in the ASB than on the milled surface. In particular, when the cutting speed and feed rate were increased to 350 m/min and 0.30 mm/tooth, the grain size in the ASB decreased from 14 to 0.68 and 0.44 µm, while in the topmost milled surface, it reduced to 7.06 and 6.75 µm, respectively. Conversely, microhardness exhibited an inverse correlation with grain size and increased with cutting speed and feed rate. Furthermore, the impact of increased plastic strain and temperature on the grains during chip segmentation was also examined. Finally, the proposed FE model validity was established by comparing simulated results with experimental data using advanced characterization techniques. This research significantly contributes to a comprehensive understanding of microstructural evolution and its implications for the mechanical performance of machined titanium components. [ABSTRACT FROM AUTHOR]

Continuous growth of the manufacturing sector is resulting in to higher energy demand due to which the manufacturing costs and greenhouse gas emissions are also increasing. Beside reduction in energy consumption; improvement in energy efficiency, power factor and reduction in cutting temperatures are also vital to ensure better sustainability of the machining sector. This work evaluates the trade-offs between energy, heat generation and cutting quality during milling of medium carbon steel (EN8) alloy steel. The effects of input process parameters viz. spindle speed, feed rate, axial depth of cut, radial depth of cut and tool helix angle has been studied on the energy consumption, energy efficiency, power factor, cutting temperatures, surface roughness response parameters. The inclusion of helix angle as an input factor and, using energy efficiency and power factor as output parameters are the major highlights of this work. The machining experiments were conducted using response surface methodology for design of experiments. The multi objective optimization was carried out by using desirability approach, for three different groups of response variables considering the different importance of energy consumption, cutting temperatures and surface roughness, under different manufacturing circumstances. The predictability of the multiple regression approach was found to be more than 90% for all the responses which highlights model significance. The direct and interaction effect were studied and discussed in details for all the responses. The values of the composite desirability achieved in all the three types of optimization problems were on higher side (0.813, 1 and 0.794). The results of the optimization were confirmed by conducting the experiments the optimized settings. The percentage error between experimental and RSM predicted result was found to be within acceptable limits. This study can be helpful for reducing the energy consumption and cutting temperature without compromising on surface roughness, in the machining of medium carbon steel. [ABSTRACT FROM AUTHOR]

Spheroidal graphite cast irons have increased ductility, tensile strength, and toughness compared to other cast irons. Additionally, it can be mentioned that choosing spheroidal graphite cast iron over steel material has a better machining feature. In this study, Face milling operations were carried out using GGG60 material and different inserts, feed, and depth of cut. The Taguchi method was used for the experimental design, and 27 experiments were carried out. During the experiments, a thermal camera measured the temperature from the cutting zone. Experimental results were evaluated with analysis of variance and graphics, and cutting parameters were optimized. As a result of the optimization, optimum parameters for minimum temperature, TiAlN coated insert, 300 m/min cutting speed, 0.30 mm/tooth feed rate, and 0.5 mm depth of cut were found. According to the results obtained from the study, the most influential parameter affecting the temperature was the cutting speed. In addition, the TiAlN-coated insert has been observed as the most suitable coating type for minimum temperature.

The 1.4306 austenite stainless steel has been prominently utilized as a material in the automotive and aerospace industry. Considerable interest has been garnered in the machinability of stainless steel owing to its high strength and poor thermal conductivity. The aim of this study is to ascertain the influential cutting parameters, specifically the cutting speed and feed rate, on cut-ting forces, cutting temperature, and chip evaluation. Thus, austenite stainless steel was subjected to free-cutting using a carbide recessing tool under dry conditions. The principle of measuring cutting temperature, a complex procedure due to varying thermal homogeneity, was elucidated. For the turning experiments in question, the standard Taguchi orthogonal array L9 (32), featuring two factors and three levels, was employed. The experimental results were analyzed using MiniTab 17 software. The findings reveal a substantial effect of feed rate on cutting force, cutting temperature, and chip evaluation. The highest cutting force and cutting temperature were observed at a feed rate of 0.15 mm/rev. Conversely, the cutting force was minimized at a cutting speed of 100 m/min, indicating potential for increasing the cutting speed. The augmentation of feed rate led to chip compression and discoloration, attributed to elevated cutting force and a larger chip cross-section that efficiently dissipates heat from the cutting zone.

This research explores how amplitude, vibration frequency, cutting depth, and aluminum content affect the micro-cutting of 7A09 aluminum composites with CoCrFeNiAlX high-entropy alloy particle reinforcement. Through simulations, we compare conventional cutting (OC) to ultrasound elliptical vibration cutting (UEVC), assessing the mechanical behavior of the material. Findings show that UEVC generates higher temperatures than OC, but these can be mitigated by optimizing parameters, notably by reducing Y-axis amplitude from 90 to 30 μm, which lowers the temperature by 27%. Aluminum content is directly proportional to cutting temperature, with Al0 content yielding a temperature roughly 95% that of Al1.UEVC consistently results in lower cutting forces compared to OC, with the most significant reduction (32 occurring at X-axis 120 μm and Y-axis 30 μm amplitudes with a 25 kHz vibration frequency. Cutting forces increase with the aluminum content in the particles. Chip integrity is superior in OC, while UEVC predominantly produces ribbon-like chips. Stress in the chip layers is mostly concentrated in the primary deformation zone for Al0 and Al1 materials, whereas it is distributed more evenly in Al0.6, with stress levels ranking from highest to lowest as Al1, Al0, and Al0.6. This study illuminates the complex interactions between cutting conditions and material composition in high-entropy alloy particle-reinforced aluminum composites. [ABSTRACT FROM AUTHOR]

SiCp/Al composites have excellent properties that traditional metals cannot match and have broad application prospects in the automotive industry, precision instruments, and other fields. However, due to the significant differences in physical properties between SiC particles and aluminum matrix, as well as the non-uniform distribution of particles in the aluminum matrix, SiCp/Al composites have strong difficult-to-process properties, which restricts the engineering application of SiCp/Al composites. This paper mainly reviews the research status of SiCp/Al composites in chip morphology and its formation mechanism, machining surface quality, cutting force, cutting temperature, and auxiliary machining and looks forward to its future research direction, which is of positive significance to promote the further development of this material. [ABSTRACT FROM AUTHOR]

A solution to the problem of determining the components of the cutting force and the cutting temperature when turning an aluminum matrix cast composite material is presented. The components of the cutting force and the cutting temperature when processing an aluminum matrix cast composite material with a hard alloy were taken as the optimization parameters. The studies were carried out using a specially designed experimental setup that consists of a lathe and a bench for recording, monitoring, and analyzing dynamic processes in the form of a signal from the cutter during turning. The computer and mathematical processing of the results obtained was carried out using the least squares method, which made it possible to derive the calculation equations to determine the factors under study. The optimal values of the factors corresponding to the optimal cutting force components and the corresponding cutting temperatures are determined. [ABSTRACT FROM AUTHOR]

Minimum quantity lubrication (MQL) as a sustainable technology has gained popularity in addressing the conflict between environmental protection and the machining requirements during cutting processes. However, conventional MQL systems employ pneumatic atomization, resulting in the generation of oil droplets with large particle sizes and uneven distribution, eventually leading to the inadequate lubrication performance of the MQL jet. In this case, the present study employed a combination of ultrasonic atomization and MQL technique to propose a novel cooling and lubrication approach and fabricate the ultrasonic vibration–assisted MQL (UVMQL) device. Geometric parameters of the ultrasonic vibrator of this device were designed and optimized using the theoretical design and finite element simulation techniques. Additionally, the impedance and amplitude detected to evaluate the performance of the UVMQL device. Subsequently, the comparative experiments were carried out under five cooling and lubrication conditions in machining of ultra-high strength steels: dry cutting, wet cutting, high-pressure air cooling, MQL, and UVMQL. Then, the machining performance of the UVMQL was discussed, in terms of cutting forces, cutting temperature, surface roughness, surface topography, and chips. Results demonstrate that in comparison to MQL, UVMQL has a lower cutting force by 5.3 N, leading to the formation of a more effective oil film lubrication layer. Due to the excellent penetration of fine oil droplets, UVMQL possesses a slightly higher cutting temperature than that of wet cutting by 43 °C, whereas results in optimal surface roughness value (Ra = 0.3 µm) and surface topography of the workpiece. Additionally, under UVMQL condition, the length of chip bonding zone is reduced by 39.8%, and the sawtooth height of chip is decreased by 35.9% compared to dry cutting. [ABSTRACT FROM AUTHOR]

With the flood cooling technique approach, it is impossible to fulfill the concerned environmental regulations and increase productivity while machining material that is infamously tough to cut. To address the conscious environmental regulation in the metal cutting industry, an effect must be made to reduce the industry process impact on environmental pollution along with manufacturing process optimization. Therefore, an eco-friendly MQL technique was investigated associated with machinability characteristics and compared results with dry condition while end milling of Inconel 825 material. The results revealed that MQL significantly reduced cutting temperature (CT) and surface roughness (Ra) to maximum levels of 70% and 43%, respectively. Further, optimum conditions were found using Taguchi method under MQL cooling. Additionally, using 3D surface plots, the interaction impact of process parameter on "Ra" has been investigated. For end milling Inconel 825 material, the MQL machining method has been proven as the most feasible alternative over dry condition. [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]

In this paper a model of the feed drive system with disturbance force for High Speed Cutting (HSC) linear motor machine tool tool is given. The dynamic stiffness for the proposed model is analysed. A simulation of the influence of some parameters on feed drive dynamic stiffness is performed with the simulation program MATLAB & SIMULINK. Correctness of the proposed model is verified with an experimental measurement of the dynamic stiffness of the feed drive on the prototype HSC linear motor machine tool (HSC 11). [ABSTRACT FROM AUTHOR]

This study employs multivariable linear regression to anticipate cutting temperature in aluminum alloy milling utilizing input parameters including three cutting conditions. Empirical data from sixty experimental tests employing an infrared thermal camera were collected to analyze temperature fluctuations during the milling process. The results indicate a high accuracy of 93.48% in predicting cutting temperature. Moreover, the investigation emphasizes the predominant influence of cutting speed "Vc" on temperature, with feed rate "fz" and depth of cut "ap" following as secondary factors. It concludes that lower speed, minimum feed rate, and maximum depth result in preferable temperatures, enhancing surface quality. The develozped regression model proves its efficacy in predicting temperature, making it a cost-effective and time-efficient tool for manufacturing applications. [ABSTRACT FROM AUTHOR]

In this work, an experimental study was carried out to investigate the influence of the cutting parameters namely cutting speed (V c) , feed per tooth (f z) , and depth of cut (a p) on three machining performance aspects, including cutting temperature (Q s) , surface roughness (R a) , and microhardness (H) when milling of AISI 1060 steel. Response surface methodology (RSM) was used for evaluating and predicting the impact of the considered cutting parameters on the selected machining characteristic indices. The results revealed that the error rates of the developed models compared to experimental ones were found to be as follows: 3.19% for Q s , 5.32% for R a , 1.63% for H , These error rates underscore the robustness and reliability of the developed models in accurately predicting the respective machining characteristics. Moreover, this study stands out in its approach by leveraging the experimentally developed RSM models as constraints within the optimization framework, providing a more precise and tailored approach compared to relying on generalized empirical models commonly found in industry handbooks. This is why a multi-objective optimization using genetic algorithm (GA) was performed to minimize both the production time and the production cost per unit by defining the problem with three key cutting parameters and utilizing the experimentally derived response surface methodology (RSM) models as constraints. For instance, the (R a) and H -based RSM model served as constraints ensuring surface roughness and microhardness values below a specified threshold while satisfying other machining constraints (tool life, cutting force, cutting power). As a result, a set of optimal solutions of combinations of cutting parameters is achieved for simultaneously minimum production time and cost per unit. [ABSTRACT FROM AUTHOR]

The titanium alloys are widely used in aeronautical engineering and medical device materials due to exceptional mechanical properties such as tensile resistance and toughness of fractures. High thermo-mechanical loads occur in metal cutting of Titanium alloy Ti6Al4V, which can decrease life of cutting tool and increase cost of part production. In this paper, the coolant effects on the cutting temperature, surface roughness and tool wear are investigated by using the developed virtual machining system. The cutting forces during turning operations of Ti6Al4V alloy are accurately calculated in order to be used in calculation of cutting temperature and tool wear. The modified Johnson–Cook methodology is utilized to obtain the cutting temperatures along machining paths. Then, the Coupled Eulerian-Lagrangian (CEL) approach is investigated to predict and evaluate the effects of coolants on the cutting temperature in turning operations of Ti6Al4V alloy. The finite element approach is employed to predict tool wear by using the Takeyama–Murata analytical model and modifying the cutting tool geometry during the chip production process. To verify the developed methodology in the study, the results of experiments for the measured cutting temperatures, surface quality and wear rate are compared to the results of virtual machining system obtained by the finite element simulation. Thus, utilizing the proposed virtual machining system in the study, cutting temperatures, surface quality and tool wear during the turning operations of Ti6Al4V alloys with and without coolant can be accurately predicted to enhance the accuracy as well as productivity in the CNC machining operations. [ABSTRACT FROM AUTHOR]

Gear skiving has been paid more and more attention for high efficiency and wide application in gear manufacturing. In gear skiving, prediction of cutting temperature and optimization of process parameters have an important influence on increasing tool life, improving machining quality and decreasing residual stress. In this study, firstly, according to the kinematic theory of gear skiving, the entity models of the skiving tool and the workpiece are established, and then the cutting temperature nephograms on the rake face of single tooth during the cutting process are obtained based on Deform software. Secondly, aiming at the influences of the cutting velocity, feed rate and shaft angle on the maximum cutting temperature on the rake face, the prediction model of the cutting temperature under multiple parameters is established by response surface methodology. Finally, a method of process parameter optimization is proposed to maximize the machining efficiency with the constraint of cutting temperature. Combined with three groups of optimization examples, the validity of the cutting temperature prediction model is verified by comparing the error between the predicted values and simulation results under the optimized parameters. The results show that the shaft angle has the greatest effect on the cutting temperature under single parameter, the cutting velocity-shaft angle has the greatest effect on the cutting temperature under multiple parameters, and the optimized predicted values are within a reasonable error range from the simulation results. The results of this study provide methodological support for improving the machining quality and tool life in gear skiving.

Abstract Superalloy Inconel718 is an important material for aircraft preparation because of its excellent performance at high temperatures. However, when cutting Inconel718, a large amount of cutting heat will be generated, resulting in excessive tool temperature and serious wear, which accelerates the tool failure. In order to solve this problem, the influence of tool angle on the process of thermal aided machining was studied by simulation model combined with thermal aided machining technology. During the cutting process, the workpiece preheating temperature rises from room temperature 20° C to 500° C, the front tool angle range is − 5° to 10°, and the rear tool angle range is 4° to 16°. By analyzing various parameters, it was found that a smaller tool rake angle can effectively reduce the tool temperature. Additionally, a flank angle of around 12° was found to decrease the maximum wear area of the tool by approximately 10.5%. Moreover, it was observed that implementing heat-assisted machining can result in a significant reduction of tool temperature by 11.1%, as well as a decrease in cutting force ranging from 18 to 22%, particularly at temperatures exceeding 500 °C.

The paper presents the results of the study of the end milling temperature of low-alloy steel depending on the cutting modes and the type of crystalline structure. The experiment was carried out on a PROMA FHV-50PD universal milling machine. The blanks were processed using a 12-12D-30C-75L-4F HRC55 carbide milling cutter. No cooling was used during processing. The obtained data were statistically analyzed to identify the dependence of the end milling temperature of low-alloy steel on the processing modes and the steel crystalline structure. When creating a mathematical model of cutting temperature, the authors carried out a bootstrap analysis to identify the significance of the parameters of the processing modes. The mathematical model was chosen using the Akaike informative criterion. It was found that mathematical models of the temperature dependence on processing modes for both types of crystalline structure include the cutting depth in the second power. At the same time, for steel in an ultrafine-grained state, both the cutting depth and the feed are statistically significant. It was not possible to detect the influence of cutting speed on temperature in the studied range of processing modes. Thus, when milling this group of materials, the force component primarily determined by the cutting depth exerts the predominant influence on the temperature regime. The level of cutting temperature when processing steel in an ultrafine-grained state is generally higher than when processing steel in a coarse-grained state, which should be associated with the increased physical and mechanical properties of steel with an ultrafine-grained crystalline structure.

The metal cutting industry faces challenges in machining hard materials due to high forces and temperatures. This paper introduces bubble-bursting atomization minimum quantity lubrication (BBA-MQL), a novel MQL technique that generates fine biodegradable oil mists for cooling and lubrication. Although the initial results of BBA-MQL are promising, there has not been a comprehensive investigation into its use in machining hard materials, specifically tool steels. Therefore, this study focused on the applicability of BBA-MQL in face milling of AISI P20 + Ni tool steel in comparison with dry cutting and conventional MQL using commercial and vegetable oil. The machining tests were performed at three cutting speeds (50, 80, and 110 m/min), fixed cutting depth (0.2 mm), and feed rate (0.15 mm/tooth). The performance is evaluated by measuring the cutting force, surface quality, cutting temperature, and tool wear. It was found that BBA-MQL decreased cutting force and surface roughness considerably, with the average reductions being 23.2 % and 49.8 % compared with the conventional minimum quantity lubrication. The highest cutting speed of 110 m/min was preferred for achieving the lowest roughness value and cutting force when milling tool steel P20 + Ni. Furthermore, BBA-MQL with castor oil proved more effective compared to conventional MQL in reducing cutting force, showing improved surface finish, reduced cutting temperature, and delayed tool wear.

In this study, mahogany seed oil was sourced and prepared, and the performances were compared with mineral oils. The extracted oil was characterized to recognize properties related to pyto-chemical, physio-chemical lubricity and thereafter used along with mineral oil for the formulation of cutting fluid using emulsifying agent, anti-corrosive agent, biocides, and anti-foam agent as additives. These additives were added to oil and water by using 24 full factorial design to achieve the optimal combination. In addition, central composite design (CCD) was adopted for the experimental design, and the performance of the mahogany oil-based cutting fluid (MBCF) was investigated in terms of surface finish, cutting temperature, material removal rate, machine sound level, and chips formation and, thereafter, compared with conventional mineral oil (CBCF) in turning of AISI 304 steel under flood cooling technique. Experimental data were analyzed using analysis of variance (ANOVA) and grey relational analysis (GRA). The experimental findings showed that optimal multi-response performance of the MBCF can be achieved using spindle speed, feed rate and depth of cut of 1100 rev/min, 0.27 mm/rev, and 0.23 mm, respectively, while optimal multi-response performance of CBCF can be achieved with spindle speed, feed rate, and depth of cut of 900 rev/min, 0.62 mm/rev, and 0.23 mm, respectively. [ABSTRACT FROM AUTHOR]

High speed machining (HSM) is an attractive process for numerous applications due to its potential to increase production rates, reduce lead times, lower costs, and enhance part quality. In this study, high-speed turning operations on AISI D2 steel using a coated carbide cutting tool under dry conditions were conducted. The cutting parameters examined in this investigation were Vc, f , and ap, while the outputs measured were surface roughness (Ra), cutting temperature (T), and flank wear (VB). To obtain reliable and accurate results, a Taguchi L27 orthogonal array for the 27 experimental runs was employed as well as analysis of variance (ANOVA), response surface methodology (RSM), and artificial neural network (ANN) to develop a constitutive relationship between prediction responses and the cutting parameters. The ANOVA results showed that Vc had a significant effect on T (36.81%) and VB (27.58%), while f had a considerable influence on Ra (24.21%). Additionally, nonlinear prediction models were created for each measured output and their accuracy was evaluated using three statistical indices: coefficient of determination (R 2), mean absolute percentage error (MAPE), and root mean square error (RMSE). Finally, multi-objective optimization was successfully carried out using the desirability function (DF) approach to propose an optimal set of cutting parameters that simultaneously minimized Ra, T , and VB. The optimized cutting parameters were Vc = 477.28 m/min, f = 0.08 rev/min, and ap = 0.8 mm, resulting in Ra = 1.23 μ m, T = 1 2 9. 9 ∘ C, and VB = 0.049 mm. [ABSTRACT FROM AUTHOR]

TiB2 particle reinforced high-stiffness steel is one of the composite materials that aim to improve Young's modulus by compositing TiB2 particles into a stainless steel base phase. This material is designed to exhibit higher rigidity and strength than conventional iron-based materials by using TiB2 particles as the reinforcing phase, and is expected to reduce the weight of high-load components in engines. For this reason, tool life is very short when machining this material. Therefore, high Young's modulus steel containing TiB2 particles is known to be one of the most difficult-to-cut materials. The purpose of this study was to investigate how to extend tool life in the milling of high-Young's-modulus steel. Cutting speed dependence of tool life was investigated by end milling using a binderless CBN tool with excellent hardness and bending strength. In addition, the tool damage mechanism was also investigated. The results showed that tools composed of binderless CBN tool have a longer life than conventional CBN tool. In this type of binderless CBN tool, the tool wear rate tended to increase with increasing cutting speed. In addition, the longest tool life was obtained at a cutting speed of 1.25 m/s, though wear rate increased at a boundary cutting length of 1300 m. The wear rate was found to increase with increasing cutting speed. Temperature measurement results indicate that the primary cause of tool damage was mechanical wear, as the temperatures were much too low for a reaction between cBN and Fe. Friction tests revealed scratch marks on the tool originating from crushed cBN particles produced by the crushing of the cutting edge. This indicates that wear is accelerated by the high frictional energy of the cBN powder rubbing against the flank face. [ABSTRACT FROM AUTHOR]

Skiving has potential for gear machining, but its cutting force fluctuates greatly, its cutting temperature is high during processing, and it has the characteristics of thermomechanical coupling. It is difficult for traditional methods to dynamically predict the thermomechanical coupling during the skiving process, whose efficiency and stability cannot be guaranteed. Aiming to solve these problems, a digital twin (DT)-based dynamic method is proposed to predict thermomechanical coupling in the skiving process. Considering the time-varying characteristics and coupling of the cutting force and temperature, a multi-physical modeling method dual-driven by mechanism and data is proposed to establish a thermomechanical coupling DT (TMDT) model of the skiving process. The dynamic consistency of the skiving process between the digital and physical spaces is realized. Principal component analysis (PCA) and an extreme learning machine (ELM) are used to reduce the order of the TMDT, the reduced-order model is trained using the skiving big data, and a relationship mapping model of the cutting parameters and the cutting force and temperature is established to realize the dynamic prediction of the cutting force and temperature. The effectiveness of the proposed method is verified through gear skiving experiments. This research has important theoretical guiding significance to realize efficient and stable skiving processing. [ABSTRACT FROM AUTHOR]

Superalloy Inconel718 is an important material for aircraft preparation because of its excellent performance at high temperatures. However, when cutting Inconel718, a large amount of cutting heat will be generated, resulting in excessive tool temperature and serious wear, which accelerates the tool failure. In order to solve this problem, the influence of tool angle on the process of thermal aided machining was studied by simulation model combined with thermal aided machining technology. During the cutting process, the workpiece preheating temperature rises from room temperature 20° C to 500° C, the front tool angle range is − 5° to 10°, and the rear tool angle range is 4° to 16°. By analyzing various parameters, it was found that a smaller tool rake angle can effectively reduce the tool temperature. Additionally, a flank angle of around 12° was found to decrease the maximum wear area of the tool by approximately 10.5%. Moreover, it was observed that implementing heat-assisted machining can result in a significant reduction of tool temperature by 11.1%, as well as a decrease in cutting force ranging from 18 to 22%, particularly at temperatures exceeding 500 °C. [ABSTRACT FROM AUTHOR]

Due to its inherent high hardness, strength, and plasticity, tantalum–tungsten (Ta-W) alloy poses a considerable challenge in machining, resulting in pronounced tool wear, diminished tool lifespan, and suboptimal surface quality. This study undertook experiments utilizing uncoated carbide tools, TiAlN-coated carbide tools, and AlTiN-coated carbide tools for machining Ta-2.5W alloy. The investigation delved into the intricacies of surface temperature, tool longevity, and the distinctive wear characteristics under varying coating materials and cutting parameters. Concurrently, a comprehensive exploration of the wear mechanisms affecting the tools was conducted. Among the observed wear modes, flank wear emerged as the predominant issue for turning tools. Across all three tool types, adhesive wear and diffusion wear were identified as the principal wear mechanisms, with the TiAlN-coated tools displaying a reduced level of wear compared to their AlTiN-coated counterparts. The experimental findings conclusively revealed that TiAlN-coated carbide tools exhibited an extended tool lifespan in comparison to uncoated carbide tools and AlTiN-coated carbide tools, signifying superior cutting performance. [ABSTRACT FROM AUTHOR]

In this study, two distinc cutting tools, coated carbide and cermet, were used in turning 20NiCrMo2 case-hardened steel. Turning experiments were carried out with these tools at three distinc cooling methods (dry, MQL, nano-MQL), three distinc cutting speeds (80, 120, 160 m/min) and three distinc feed rates (0.125, 0.167,0.2 mm/rev) has been carried out. As a result of the experiments, the effects of cutting parameters, cutting tool type and cooling method type on the average surface roughness (Ra) and cutting zone temperature (Ctemp) were examined. In the study, the Taguchi optimization method was also applied to the experimental Ra and Ctemp results. As a result of Taguchi optimization, the most effective cutting parameters on Ra and Ctemp were determined. This result was confirmed by ANOVA analysis. Optimum parameters for Ra; cermet cutting tool, nano-MQL cooling method, 160 m/min cutting speed and 0.12 mm/rev feed rate. Optimum parameters for Ctemp; carbide cutting tool, nano-MQL cooling method, 80 m/min cutting speed and 0.12 mm/rev feed rate. Ideal numbers for both Ra and Ctemp were not found in the 18 turning experiments performed. Therefore, the 19th experiment was conducted for both output parameters. The average surface roughness value for optimum parameters was measured as 1.08 pm. [ABSTRACT FROM AUTHOR]

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The nozzle arrangement of internal spray cooling tool plays a crucial role in the efficiency of coolant flow into the cutting zone and has a significant impact on the cutting performance. This article designs three types of internal spray cooling turning tools based on the different arrangements of the upper nozzle on the tool rake face. Tool A has an upper nozzle near the main cutting edge, tool B is equipped with an upper nozzle near the minor cutting edge, and tool C possesses two upper nozzles near the main and minor cutting edges, respectively. The nozzle arrangement effect on the cooling performance of the internal spray cooling turning tool during the internal turning process was studied by the fluid–solid-thermal coupling simulation method. The simulation results showed that tool B with an upper nozzle arranged near the minor cutting edge had the best cooling performance because it is easy for air and coolant droplets to enter the tool-chip contact zone. On the contrary, tool C equipped with two upper nozzles near the main and minor cutting edges results in the worst cooling performance for the air and coolant droplets are difficult to flow into the tool-chip contact area. Internal turning experiments of QT500-7 workpieces were carried out. Results demonstrated that tool B performed best in reducing cutting temperature and improving machined surface quality. In addition, the number of small chips generated by all internal spray cooling turning tools increased at an inlet pressure of 0.6 MPa, especially for tool B. [ABSTRACT FROM AUTHOR]

High cutting temperatures increase tool wear and reduce tool life. To achieve a longer tool life, coated carbide tools have been developed. In this study, the influence of tool coatings on the cutting temperature distribution during the orthogonal cutting of H13-hardened steel is investigated. Firstly, four coating materials, including TiC, TiN, Al2O3, and TiAlN, with the same coating thickness, are selected to evaluate the effects of coating materials on cutting temperature with finite element simulation. The maximum temperatures at the tool rake face and the temperatures at the coating–substrate interface are evaluated. It was found that the maximum temperatures at the tool rake face were the lowest and the highest when TiN and Al2O3 coating materials were applied, respectively. The TiAlN coating material had the best thermal barrier property. Then, the temperature distribution along the direction perpendicular to the tool rake face is investigated for TiAlN-coated tools with different coating thicknesses ranging from 3 μm to 10 μm. It is shown that the temperature gradient increases with the coating thickness. The coating thickness should be kept below 5 μm. Finally, cutting experiments validate the availability of the finite element model. [ABSTRACT FROM AUTHOR]

The main study objective was to evaluate the influence of the perspective "Internal" (coolant is supplied to the channel inside the indexable insert body) and "Combined" (coolant is supplied to the rake and flank faces through the channel inside the indexable insert body) Cooling Schemes on the temperature of the contact point between the tool and the workpiece, on the heat distribution inside the indexable insert body, and (additionally) on the cutting forces. The contact point temperature and cutting forces were investigated during the non-orthogonal turning of SUS304 Stainless Steel at speeds of 180, 140, and 100 m/min with constant feed and depth of cut. The heat distribution was examined through 2D simulations using DEFORM 2D3D software. The evaluation of the perspective cooling schemes' influence on the selected parameters was performed by comparing the obtained data with the test results of the "traditional" external cooling and dry cutting under similar cutting modes. According to the comparison results, the perspective cooling schemes demonstrated a slight decrease (~3-7%) in the temperature of the contact point between the tool and the workpiece, a significant decrease in the heat distribution (~38-55%) inside the indexable insert body and, in some cases, a decrease of the cutting forces. Based on the study results, the authors confirmed the influence of perspective cooling schemes on the selected parameters and suggested a further positive effect of these schemes' utilization on the cutting tool life.

This study aimed to analysis open‐hole tensile strength, pin-bearing strength, cutting temperature, and surface roughness of drilled thin glass fiber reinforced polymer composites. The specimens were clamped from both sides during drilling operations. The cutting temperature was measured using high resolution infrared camera. Surface roughness was evaluated by seven parameters to identify the most suitable ones. Multiple regression models were developed to predict critical thrust force (CTF), critical feed, and cutting temperature in drilling operations. The measurements indicate that the cutting temperature is higher than the matrix's glass transition temperature and hence, the surface roughness paramaters Ra, Rq and Ry are increased at the maximum cutting conditions by 57%, 51%, and 36% respectively. In contrast, the bearing strength improved by 13%. This peculiar phenomenon was deeply analyzed with the aid of short ageing effects on the post curing, which increase the crosslinking density within the composites and improve the matrix's capacity to efficiently transmit the loads to the reinforcing fibers. For the first time, the optimum cutting conditions were determined based on the optimum short ageing parameters (temperature and time). Supported drilling increases CTF by 23%, which can reduce machining time and manufacturing costs with fewer delamination concerns.

Cutting tools made of the WC-Co sintered carbides are now very popular and are widely used in machining of materials. However, there are numerous problems in this area which require more research and need to be studied further. This paper presents the results of an experimental study aimed at discovering the impact of the microstructure, particularly of the tool substrate grain size, on the quality of the machined surface, cutting forces and temperature in the cutting zone, as well as the tool life. In addition, the impact of the feed was considered. The machining process involved side milling of a cuboidal block made of the AISI 316L steel which, due to its specific properties, is widely used in many industries. The tools used in the tests had different WC phase grain size: 0.18, 0.28 and 0.31 μm, respectively, and moreover the middle specimen had also a non-homogeneous structure and an increased content of the Co matrix. The tests proved a significant impact of the tool microstructure on the tool life and the roughness parameters Ra and Rz of the machined surface. The impact of the studied factors on the forces and the temperature in the cutting zone was not as strong, because it did not exceed 20%. The value and the novel character of the paper results from the fact that it concerns a specific case: side milling of the 316L steel with the use of the WC-Co sintered carbide tools, and consequently provides a contribution to solve a practical industrial issue.

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.

This study focused on determining the effects of the cooling condition in the conventional and ultrasonic-assisted turning of AISI 52100 steel. AISI 52100 steel has been widely used in the bearing, mold, and automotive industries because of its superior wear resistance and mechanical properties. However, its high wear resistance caused poor machinability in conventional machining methods. Low surface quality, rapid tool wear, high cutting temperature, and high cutting force are the main difficulties in the conventional machining of AISI 52100 steel. On the other hand, ultrasonic-assisted machining has become widely used in the past decades for the machining of materials that have low machinability in conventional methods. Conventional turning and ultrasonic-assisted turning were selected as machining methods. Ultrasonic-assisted turning experiments were conducted under 20 and 30 kHz vibration frequencies. Cubic Boron Nitride (CBN) cutting tools were used in machining experiments. In machining operations 50, 100, and 150 m/min cutting speeds were selected, and feed rate (0.1 mm/rev) and depth of cut (0.5 mm) were kept constant in experiments. Minimum quantity lubrication technique which used 1% Al2O3 nanoparticle additives cutting fluid and dry cooling methods were used. CBN insert was used as a cutting tool. The effects of cutting speed, cutting method, and cooling condition on surface quality, cutting force, cutting zone temperature, and cutting tool wear were studied experimentally. Analysis of Variance (ANOVA) was carried out to determine the significance of the effects of input variables on process outputs. As a result of this study, it is determined that combined UAT and nanoMQL have significant effects on the process outputs. [ABSTRACT FROM AUTHOR]