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When micro-single-lip deep hole drilling the efficiency of the cutting fluid supply cannot be investigated experimentally due to the inaccessibility of the cutting zone. For this reason, this paper examines the cutting fluid behavior, taking into account the chip formation and the transient chip position, with the help of various combined simulation methods. Therefore, experimentally obtained chips are digitalized and converted into a Computer-Aided Design model for the following simulations. Furthermore, for a comparison of the simulations with the experiments, the velocity of the cutting fluid in the chip flute of the tool is measured by a similar Particle Image Velocimetry method. Then, a transient coupled particle simulation of Smoothed Particle Hydrodynamics and the Discrete Element Method is performed to obtain the transient chip positions along the chip flute under the influence of the cutting fluid. Based on these chip positions, a Computational Fluid Dynamics simulation follows to derive insights about the flow field and pressure field at certain points in time. This multi-physics simulation chain allows to deal with experimental results in a simulation context to gain further insights about the deep hole drilling process, which are experimentally inaccessible and allows further connections between experiment and simulation. [ABSTRACT FROM AUTHOR]

Thin wafers and thin wires are beneficial to the photovoltaic industry for reducing costs, increasing efficiency, and reducing the cost of electricity generation. It is a development trend in solar silicon wafer cutting. Thin wire cutting reduces the kerf between silicon wafers to less than 50 μm. Therefore, it is extremely difficult to supply cutting fluid to the cutting area. And this affects cutting performance. This paper proposes the use of the capillary effect produced by ultrasonic waves in fixed diamond wire slicing to improve the cutting fluid supply and reduce wafer adsorption. To explore the rules of ultrasonic capillary action between two plates and guide the industrial applications, the effects of the distance between parallel plates, the distance from the bottom of the parallel plates to the ultrasonic radiation surface, the non-parallelism between the plates, the temperature of the working fluid, the ultrasonic action time, and the type of working fluid on the liquid level rise height were studied. The conclusions can be used to guide the improvement of the supply of working fluid in fixed diamond wire slicing. [ABSTRACT FROM AUTHOR]

In this paper, we focus on the temperature sensing and data collection of milling tools during the machining process. The collected data is visualized in real-time dynamic charts using the ThingSpeak platform. In case of temperature abnormalities, users are notified via LINE for inspection or tool replacement. The control system is implemented using a flexible printed circuit board embedded within the concentric cylinder of the milling cutter's handle. The Arduino programming language is used for programming, and temperature measurement is achieved through a K-type thermocouple module combined with an ESP32 microcontroller, utilizing Wi-Fi to transmit data to the ThingSpeak platform for real-time monitoring on computer screens. The system's advantage lies in enabling users to monitor the temperature of milling tools, preventing tool dullness or damage, and improving machining accuracy by reducing the frequency of tool replacement. This system is particularly suitable for milling machines that use cutting fluid. Temperature abnormalities indicate a decrease in cutting capability owing to tool dullness, resulting in increased heat generation during cutting or the insufficient cooling capacity of the cutting fluid with respect to the heat generated during cutting. Such alerts allow timely inspection or tool replacement. However, most modern milling machines come equipped with their own monitoring systems for tool wear and temperature. Hence, in this paper, we primarily focus on monitoring milling tool temperature. The uppertemperature limit for alerting is set at 290 °C on the basis of the expected hardness of tungsten carbide, which is suitable for machining up to this temperature. Currently, a warning temperature of 200 °C is used. This enables users to determine the condition of the tool during operation, ensuring safer use and facilitating better quality control and industrial safety for manufacturers. [ABSTRACT FROM AUTHOR]

With the development of the manufacturing industry, environmental problems have become more and more serious. At present, green design is playing an increasingly important role in product design and manufacturing. How to combine traditional conceptual design methods with green designs to realize green conceptual design is of great practical significance. In order to realize the green concept design of a product and to allow the conceptual design scheme to meet the functional requirements and green performance requirements of the product at the same time, this study introduces the knowledge push process and the green filter process into product concept design. The knowledge of invention principles is retrieved by establishing the knowledge space of invention principles, by calculating the word segmentation based on the CRF (conditional random field), and calculating the word similarity using a thesaurus. This is performed in order to realize the transformation from product function requirements to invention principle knowledge. Then, by studying the relationship among the environmental efficiency factors, green design attributes, engineering technical parameters, and invention principles, the correlation mapping table for green design attributes and invention principles is established. Thus, the green filter is applied to the pushed knowledge according to the green performance requirements, so that the final push results after filtering can meet the functional and green performance requirements of the product. In the last section of this paper, a green concept design for cutting the fluid supply system in an enterprise is presented as an example to verify and analyse the proposed method. [ABSTRACT FROM AUTHOR]

Using cutting fluids is considered in industrial applications and academia due to their increased influence over many aspects such as machinability, sustainability and manufacturing costs. This paper addresses the machinability perspective by examining indicators such as roughness, cutting temperature, tool wear and chip morphology during the milling of mold steel. A special type of steel is Nimaxm which is a difficult-to-cut material because of its high strength, toughness, hardness and wear resistance. Since mold steels have the reverse geometry of the components produced by this technology, their surface quality and dimensional accuracy are highly important. Therefore, two different strategies, i.e., dry and minimum quantity lubrication (MQL), were chosen to conduct an in-depth analysis of the milling performance during cutting at different cutting speeds, feed rates and cutting depths. Without exception, MQL technology showed a better performance than the dry condition in obtaining better surface roughnesses under different cutting parameters. Despite that only a small improvement was achieved in terms of cutting temperature, MQL was found to be successful in protecting the cutting tool from excessive amounts of wear and chips. This paper is anticipated to be a guide for manufacturers and researchers in the area of mold steels by presenting an analysis of the capabilities of sustainable machining methods. [ABSTRACT FROM AUTHOR]

Most hot dry rock geothermal wells are small angle directional wells, and rock cuttings easily accumulate at the bottom of the borehole to form a cuttings bed, causing accidents such as drill sticking, reducing the rate of penetration, and drilling tool breakage. Accurately calculating the resistance coefficient and settling velocity of hot dry rock cuttings can improve cuttings transportation efficiency, design and optimize drilling hydraulic parameters, and is crucial to solving borehole cleaning problems. Through visual experiments, this paper obtained experimental data on the settlement of 167 groups of spherical pellets, 153 groups of granite cuttings, and 174 groups of carbonate cuttings in the Herschel-Bulkley fluid. First, a prediction model for the resistance coefficient of spherical pellets consistent with Herschel-Bulkley fluid was established. Based on this, form factor-Roundness is introduced as the starting point, and two prediction models for the resistance coefficients of granite cuttings and carbonate cuttings in the Herschel-Bulkley fluid were established. The average relative errors between the resistance coefficient model predictions and experimental measurements are 9.61% for granite cuttings and 6.59% for carbonate cuttings. The average relative errors between the predicted and measured values of settlement velocity are 7.27% for granite cuttings and 6.21% for carbonate cuttings, respectively, which verifies the accuracy and reliability of the prediction model. The research results can provide a theoretical basis and engineering application guidance for optimizing drilling fluid rheology and circulation displacement in engineering. [ABSTRACT FROM AUTHOR]

In the process of oil and gas drilling, it is of great significance to accurately predict the drag coefficient and settling rate of cuttings in the drilling fluid for hydraulic parameters and borehole cleaning. In this paper, particle settling experiments were used to obtain the final settling velocity of 196 groups of spherical particles and 224 groups of terrestrial high-clay pure-shale cuttings in the power-law fluid. Based on data analysis, a settlement drag coefficient model suitable for irregular- shaped shale cuttings was established. The model can be used to predict the settlement drag coefficient and settling velocity of irregular-shaped shale cuttings in power-law fluid, which can provide theoretical guidance for wellbore cleaning and hydraulic parameter optimization in Daqing Gulong shale oil drilling operations. [ABSTRACT FROM AUTHOR]

In this paper, the authors investigated the impact of DLC coatings doped with tungsten (a-C:H:W) coatings obtained using plasma-assisted physical vapor deposition (PVD) on the properties of the 100Cr6 steel. The results of the 100Cr6 steel specimens with and without the coating were compared. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis were used to observe the morphology of the coating surfaces and cross-sections and identify the elements in the coating composition. The contact angle of the investigated surfaces was measured with a tensiometer. Additionally, the effect of the coatings on the tribological properties of lubricated friction pairs was evaluated. Friction tests were performed on a ball-on-disc tribometer under lubrication with cutting fluid. The surface texture of the samples before and after the tribological tests was measured using a confocal profilometer. The results obtained from the tests and analysis allow for the conclusion that the use of DLC coatings a-C:H:W increases the hardness of 100Cr6 steel by three times. The values of the contact angles were indicative of surface hydrophilic characteristics. The tungsten-doped diamond-like coating under friction conditions reduced the coefficient of friction and wear. DLC coatings a-C:H:W lubricated with the cutting fluid improve the mechanical and tribological properties of 100Cr6 steel sliding surfaces under friction. [ABSTRACT FROM AUTHOR]

Metal working process is one of the main activities in mechanical manufacturing industry; it is considered as a major consumer of energy and natural resources. In material removal process, the selection of cutting parameters and cooling or cutting liquid is necessary to save energy and achieve energy efficiency as well as sustainability. During the last two decades, the number of publications in this field has rapidly increased and has shown the importance of this research area. This review paper identifies and reviews in detail a total of 166 scientific studies which exhibit original contributions to the field and address multiple energy efficiency challenges. The recently developed models of energy consumption and different materials used in the machining process are presented. Therefore, this study describes various techniques for modeling and optimizing machining operations such as turning, milling, and drilling. Modeling techniques, experimental methods, multi-objective and single-objective optimization methods, and hybrid techniques optimization are presented in a detailed manner compared to previous review papers where only energy models are discussed. It can help practitioners and researchers to select the most appropriate approach for the desired experience and to highlight the progress of these methods in terms of machining energy efficiency. Additionally, this paper provides a review of different cutting fluids adopted in machining processes. This paper assists researchers and manufacturers in making advantageous technical decisions that have substantial economics in terms of energy saving. [ABSTRACT FROM AUTHOR]

Metal cutting fluids for improved cooling and lubrication are an environmental risk and a health risk for workers. Minimizing water consumption in industry is also a goal for a more sustainable production. Therefore, metal cutting emulsions that contain hazardous additives and consume considerable amounts of water are being replaced with more sustainable metal cutting fluids and delivery systems, like vegetable oils that are delivered in small aerosol droplets, i.e., via minimum quantity lubrication (MQL). Since the volume of the cutting fluid in MQL is small, the cooling capacity of MQL is not optimal. In order to improve the cooling capacity of the MQL, the spray can be subcooled using liquid nitrogen. This paper investigates subcooled MQL with machining simulations and experiments. The simulations provide complementary information to the experiments, which would be otherwise difficult to obtain, e.g., thermal behavior in the tool-chip contact and residual strains on the workpiece surface. The cBN hard turning simulations and experiments are done for powder-based Cr-Mo-V tool steel, Uddeholm Vanadis 8 using MQL subcooled to −10 °C and regular MQL at room temperature. The cutting forces and tool wear are measured from the experiments that are used as the calibration factor for the simulations. After calibration, the simulations are used to evaluate the thermal effects of the subcooled MQL, and the surface residual strains on the workpiece. The simulations are in good agreement with the experiments in terms of chip morphology and cutting forces. The cutting experiments and simulations show that there is only a small difference between the subcooled MQL and regular MQL regarding the wear behavior, cutting forces, or process temperatures. The simulations predict substantial residual plastic strain on the workpiece surface after machining. The surface deformations are shown to have significant effect on the simulated cutting forces after the initial tool pass, an outcome that has major implications for inverse material modeling. [ABSTRACT FROM AUTHOR]

The machining process of aluminum alloy usually produces built-up edge and tool sticking problems due to their low hardness and large plastic deformation, which may further affect the machined surface quality and tool life. This paper aims to investigate the influence of different cutting fluids on the machined surface quality and tool life during the milling process of 7050 aluminum alloy. A novel cutting fluid (QC-2803) was considered in the study, which is synthesized by addition of alkyl alcohol amide and chlorinated polyolefin, and the traditional cutting fluid (CCF-10) was used as the control group. The physical and chemical properties of two cutting fluids were characterized. The milling process of 7050 aluminum alloy was carried out under two different cutting fluid conditions. The machined surface morphology, cutting force and tool wear morphology were observed during the process. Results show that the surface tension of the novel cutting fluid is significantly lower than that of the traditional cutting fluid, which makes it easier to produce a lubricating film between the aluminum alloy and tool, and further benefits the machined surface quality and tool life. As a result, the surface roughness and cutting force are reduced by ~20.0% and ~42.9%, respectively, and the tool life is increased by 25.6% in the case of the novel cutting fluid (QC-2803). The results in this paper revealed the important laws of cutting fluid with metal surface quality, cutting performance and tool wear, which helps to control the machined surface quality and tool life by the selection of cutting fluid during metal milling. [ABSTRACT FROM AUTHOR]

In every conventional machining process interaction of tool interface with that of workpiece results in high temperatures and thermal distortions. Such distortions may lead to change in the surface morphology of the machined workpiece, thus harming the desired finishing of the product. The use of nanofluids as a coolant over traditional cutting fluid help in minimising such problems. In continuation to the past research on nanofluids, the use of hybrid nanofluids in machining operations is attracting the researchers. The synthesis of hybrid nanofluid is done by dispersing two different nanoparticle in traditional heat transfer fluid which can be seen as efficient coolant and lubricant. The hybrid nanofluids are found favourable in terms of thermo physical properties, heat transfer rate and stability. This has led to increase in research on hybrid nanofluids over mono type nanofluids. This paper summarises the application of hybrid nanofluids by various researchers in different machining operations namely turning, grinding, and drilling. Furthermore, the paper deals with the tribological properties of different hybrid nanofluid and the temperature control in the machining operations. [ABSTRACT FROM AUTHOR]

In the manufacturing industry, during machining, the conventional cutting fluid plays a vital role; however, extravagant use of cutting fluids due to its disposal affects the environment badly. Nowadays, due to these advantages of conventional cutting fluids, alternative methods of conventional cutting fluids or alternative methods are preferred. One of the most preferred methods may be the minimum quantity lubrication technique with conventional or nanoparticle-enriched cutting fluids. The present paper has a compilation of the investigations based on MQL application in different machining processes such as turning, milling, grinding, and drilling. The machining also involves hard-to-machine alloys. The paper discusses cryogenic MQL in brief and opens the domain for work in future. The purpose of this paper is to provide a quick reference for researchers working on the practical use of MQL lubricants with nanopowders dissolved and their application in machining for different materials. [ABSTRACT FROM AUTHOR]

Production profiling technology is an important method for monitoring the dynamics of oil and gas reservoirs which can effectively improve the efficiency of oil recovery. Production profiling is a technique in which a test instrument is lowered from the tubing to the bottom of the well to measure flow, temperature, pressure, and density in a multi-layer section of a producing well. Normal production profiling process needs to stop production, operate complex, consume long time and high cost. Furthermore, the profile cannot be continuously monitored for a long time. To address these limitations, this paper proposes a production profiling interpretation method based on reservoir primitive microbial DNA sequencing. The microbial stratigraphic baseline with high-resolution features is obtained by sampling and DNA sequencing of produced fluid and cuttings from different wells. Specifically, the random forest algorithm is preferred and improved by comparing the accuracy, precision, recall, F1-score, and running time of three clustering methods: Naïve-Bayes classifier, random forest classifier, and back-propagation classifier. Constructing PSO-random forest model is based on stratigraphic records and produced fluid bacteria features. The computational accuracy and efficiency of this method allows it to describe the production profile for each formation. Moreover, this test process does not need to stop production with simple operation and does not pollute the formation. Meanwhile, by sampling fluid production at different stages, it can achieve the purpose of long-term effective dynamic monitoring of the reservoir. [ABSTRACT FROM AUTHOR]

Purpose: Because many cutting fluids contain hazardous chemical constituents, industries and researchers are looking for alternative methods to reduce the consumption of cutting fluids in machining operations due to growing awareness of ecological and health issues, government strict environmental regulations and economic pressures. Therefore, the purpose of this study is to raise awareness of the minimum quantity lubrication (MQL) technique as a potential substitute for environmental restricted wet (flooded) machining situations. Design/methodology/approach: The methodology adopted for conducting a review in this study includes four sections: establishment of MQL technique and review of MQL machining performance comparison with dry and wet (flooded) environments; analysis of the past literature to examine MQL turning performance under mono nanofluids (M-NF); MQL turning performance evaluation under hybrid nanofluids (H-NF); and MQL milling, drilling and grinding performance assessment under M-NF and H-NF. Findings: From the extensive review, it has been found that MQL results in lower cutting zone temperature, reduction in cutting forces, enhanced tool life and better machined surface quality compared to dry and wet cutting conditions. Also, MQL under H-NF discloses notably improved tribo-performance due to the synergistic effect caused by the physical encapsulation of spherical nanoparticles between the nanosheets of lamellar structured nanoparticles when compared with M-NF. The findings of this study recommend that MQL with nanofluids can replace dry and flood lubrication conditions for superior machining performance. Practical implications: Machining under the MQL regime provides a dry, clean, healthy and pollution-free working area, thereby resulting the machining of materials green and environmentally friendly. Originality/value: This paper describes the suitability of MQL for different machining operations using M-NF and H-NF. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0131/ [ABSTRACT FROM AUTHOR]

Near–dry machining and dry machining lead to increased temperature of the cutting tools. To reduce tool wear and extend the tool lifetime, and, eventually, to keep the accuracy of manufactured parts within acceptable limits as long as possible, a sustainable cooling technique is required. The technology of internal cooling of the cutting tool appears to be the most promising, because it allows eliminating the presence of the coolant on the manufacturing part and delivers the heat–transferring fluid to the very cutting area of the tool. This paper provides a literature review on the closed–loop internally cooled cutting tools (CLICCT) for turning. The current level of knowledge and experimental machining with prototypes has proven that CLICCT can utilize the benefits of dry cooling, having a longer tool life. [ABSTRACT FROM AUTHOR]

AbstractThis literature review explores minimum quantity lubrication (MQL) machining, emphasizing its benefits over traditional dry and flooded cooling methods. MQL is vital in manufacturing, enhancing productivity and sustainability. Adding solid lubricants (SL) amplifies MQL’s advantages. This article identifies challenges in MQL + SL machining and outlines future research opportunities. A comprehensive four-step review was conducted: identifying research gaps, determining databases and search terms, defining paper selection methods and performing bibliometric analysis. The review abstracted information from selected articles, offering in-depth discussions. Challenges in MQL machining involve forces, temperature, tool wear, roughness and lubricant performance. Studies show incorporating SL into base fluids mitigates these issues. Sustainability is a core focus in modern manufacturing, and MQL’s eco-friendly reputation is deserved. MQL with SL, often in nanoparticle form, provides benefits like reduced friction, enhanced tool life, lower energy consumption and improved material disposal. In conclusion, MQL + SL machining offers a promising path to balance productivity and sustainability. Continued research and development are essential to overcome challenges and unlock its full potential. As manufacturing evolves, MQL + SL machining exemplifies innovation and sustainability, poised to reshape the industry’s future. [ABSTRACT FROM AUTHOR]

The base fluids of eco-friendly cutting fluids should contain some vegetable oil. Due to their eco-friendly, thermal, and tribological qualities, these types of machining fluids are becoming increasingly popular among researchers throughout the world. The authors summarized published research studies on the use of eco-friendly machining fluids (including nanofluids) in various metal removal processes such as turning, milling, grinding, and drilling in this review paper. The impact of several biodegradable oil-based machining fluids on performance metrics such as surface irregularity, machining force, tool wear, power demand, and temperature-induced during the machining process is also explored in this paper. According to the previous and current literature, using an eco-friendly nano machining fluid results in better surface features, less cutting tool wear, lower cutting force, less power required, and lower machining zone temperature during the machining operation due to superior cooling and lubrication properties. [ABSTRACT FROM AUTHOR]

Electrochemical multi-wire sawing (EMWS) is a hybrid machining method based on a traditional multi-wire sawing (MWS) system. In this new method, a silicon ingot is connected to a positive electrode; the slicing wire is connected to a negative electrode. Material is removed by the interaction of mechanical grinding and an electrochemical reaction. In this paper, contrast experiments of EMWS and MWS were conducted based on industrialized equipment to verify the beneficial effects of the hybrid method. The experimental statistical results show that the composite processing method improved the processing qualification rate by 1.28%, and the Bow of silicon wafers was reduced by about 2.74 microns. Further testing on the surface of the silicon wafer after electrochemical action showed that obvious holes were present on the surface, and the surface hardness of the wafer decreased significantly. Therefore, the scratches on the surface of wafer sliced by EMWS were reduced; in addition, the thickness of the surface damage layer was reduced by about 9 microns. After standard texturing, the average reflectivity of the wafers sliced by EMWS was about 2–10% lower than that of the wafers sliced by MWS in the wavelength of 300–1100 nm. In this paper, the voltage parameter of the composite machining is set to 48 V; the amount of electrolyte added in each experiment is 2 L; and a good machining effect is obtained. In the future, the electric parameters and cutting fluid components will be further studied to improve the electrochemical effect. [ABSTRACT FROM AUTHOR]

For single-lip drills with small diameters, the cutting fluid is supplied through a kidney-shaped cooling channel inside the tool. In addition to reducing friction, the cutting fluid is also important for the dissipation of heat at the cutting edge and for the chip removal. However, in previous investigations of single-lip drills, it was observed that the fluid remains on the back side of the cutting edge, and accordingly, the cutting edge is insufficiently cooled. In this paper, a simulation-based investigation of an introduced additional drainage flute and flank surface modifications is carried out using smoothed particle hydrodynamics as well as computational fluid dynamics. It is determined that the additionally introduced drainages lead to a slightly changed flow situation, but a significant flow behind the cutting edge and into the drainage flute cannot be achieved due to reasons explained in this paper. Accordingly, not even a much larger drainage flute with unwanted side-effect of a decrease tool strength is able to archive a significant improvement of the flow around the cutting edge. Therefore, major changes to the cooling channel, like the use of two separate channels, the modification of their positions, or modified flank surfaces, are necessary in order to achieve an improvement in lubrication of the cutting edge and heat dissipation. [ABSTRACT FROM AUTHOR]

This paer provides information on research on the technology of broaching of the internal shaped surfaces. This paper provides information on the research on the technology of stretching of internal shaped surfaces. It is a technology that is used in mass production. Our research was focused on machining of internal surfaces. The difficulty of the research was that it involved internal shaped complex surfaces called grooves. At the same time, the research was carried out under mass production conditions. Another problem is that in broaching, low cutting speed is used and therefore oil is commonly used as the cutting medium. The test specimens were intended for further use in assembly. The effect of changing the cutting medium on the roughness of the machined surface of the newly formed grooves was investigated. The experimental conditions consisted of obtaining data directly from a real production broaching process. Real production conditions were used and the type of cutting medium was varied. So far, oil has been used. Our intervention was to replace the oil with an emulsion. The research hypothesis was based on the fact that if, with sufficient lubricating properties of the emulsion used, the machining process will be satisfactory in terms of the prescribed surface roughness, then considerable financial costs will be saved for this process. The paper documents the occurrences for the roughness of machined grooves as a function of the change in cutting fluids. [ABSTRACT FROM AUTHOR]

This paper presents a novel cutting fluid monitoring sensor system and a description of an algorithm framework to monitor the state of the cutting emulsion in the machine tool sump. One of the most frequently used coolants in metal machining is cutting emulsion. Contamination and gradual degradation of the fluid is a common occurrence, and unless certain maintenance steps are undertaken, the fluid needs to be completely replaced, which is both un-economical and non-ecological. Increasing the effective service life of the cutting emulsion is therefore desired, which can be achieved by monitoring the parameters of the fluid and taking corrective measures to ensure the correct levels of selected parameters. For this purpose, a multi-sensor monitoring probe was developed and a prototype device was subsequently created by additive manufacturing. The sensor-carrying probe was then placed in the machine tool sump and tested in operation. The probe automatically takes measurements of the selected cutting emulsion properties (temperature, concentration, pH, level height) in set intervals and logs them in the system. During the trial run of the probe, sensor accuracy was tracked and compared to reference measurements, achieving sufficiently low deviations for the purpose of continuous operation. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to analyse the effects derived from the presence of residual coolant from machining operations on the Directed Energy Deposition of AISI H13 tool steel and the quality of the resulting part. Design/methodology/approach: In the present paper, the effectiveness of various cleaning techniques, including laser vaporising and air blasting, applied to different water/oil concentrations are studied. For this purpose, single-layer and multi-layer depositions are performed. Besides, the influence of the powder adhered to the coolant residues remaining on the surface of the workpiece is analysed. In all cases, cross-sections are studied in-depth, including metallographic, microhardness, scanning electron microscopy and crack mechanism analyses. Findings: The results show that, although no significant differences were found for low oil concentrations when remarkably high oil concentrations were used the deposited material cracked, regardless of the cleaning technique applied. The crack initiation and propagation mechanisms have been analysed, concluding that the presence of oil leads to hydrogen induced cracking. Originality/value: High oil concentration residues from previous machining operations in hybrid manufacturing led to hydrogen induced cracking when working with AISI H13 tool steel. The results obtained will help in defining future hybrid manufacturing processes that combine additive and subtractive operations. [ABSTRACT FROM AUTHOR]

In machining operations, the application of cutting fluids has been of prime importance for the extraction of heat from rake surfaces, ease of removal of the chips and reduction of friction at the chip–tool interface. These three objectives are achieved by the supply of suitable conventional cutting fluid at the machining zone using different techniques. However, the misuse of these fluids and their wrong disposal methods were found to have an adverse effect on the environment and health of human. To reduce the usage of conventional cutting fluid, minimum quantity lubrication (MQL) technique has been emerged as an alternative means in the last few years, leading to better eco-friendly. Further, to increase the sustainability of MQL technique, it becomes necessary to use an appropriate exceptional nanostructured material with MQL that could be an effective cutting fluid (i.e. nanocutting fluids) with better tribological and thermophysical properties, and might be helpful in addressing the eco-friendly problem to a great extent. Therefore, the present paper focuses on the review of important published works related to the use of mono/hybrid nanocutting fluids with MQL technique at various processing parameters in different metal cutting operations. Most of the studies have shown a significant reduction in cutting forces, temperature at cutting zone, tool wear, and friction coefficient, and considerable improvement in surface quality by the addition of mono/hybrid nanoparticles enriched cutting fluid in MQL technique as compared to dry as well as wet machining processes. Further, the paper discusses the future scope in the area of hybrid nano-cutting fluids in different machining processes. [ABSTRACT FROM AUTHOR]

The microtexture is gaining more and more attention due to its unique and excellent properties in metal cutting. However, most researchers currently only pay more attention to the performance of microtextures in dry cutting, but less on the performance under lubrication conditions. Some researches show that the microstructure performs better under lubrication conditions. In addition, most people only focus on the cutting performance of a single microtexture, and there are few studies on composite microtextures. In this study, a 2D finite element model and a fluid lubrication model of metal cutting were established by finite element software, and the cutting fluid model was introduced into the 2D finite element model. The cutting process of cuting the Ti6Al4V alloy under the auxiliary lubrication of cutting fluids was successfully simulated. The convex volcano-like texture (VLT) in this paper is a composite microtexture. At the same time, a new bionic microtexture tool is proposed to solve the problem of weakened the structural strength of the tool caused by the machining microtexture on the tool. The simulation results of cutting the Ti6Al4V alloy in both dry and wet conditions show that the cutting results of the bionic microtexture tool are superior to those of the conventional tool in both cases, and the processing effect under lubrication is greatly improved. This paper also presented a new lubrication method—small quantity lubrication (SQL), which uses up to 3.14% of the amount of lubricant required by the traditional immersion lubrication (TIL). This lubrication method makes the cooling lubrication effect even better than that of TIL, besides greatly saving cutting fluids. This paper revealed the mechanism of microtexture tools cutting under lubrication conditions, solved the problem of weakened of tool strength by machining microtexture, and proposed a new efficient, green, and economical lubrication method. [ABSTRACT FROM AUTHOR]

This paper reviews recent progress and applications of usage of cutting fluids in conventional machining processes. In addition to reviewing the various conventional and advanced cooling techniques during machining, the paper also discusses the use of minimum quantity lubrication (MQL) in several types on metals such as steel, aluminum, alloy, and titanium alloys. Due to the toxicity of conventional cutting fluid resulting in ecological problems, the demand for environmentally friendly cutting fluid is rising. Therefore, natural vegetable oil is chosen as potential replacement as an environmentally friendly cutting fluid which fulfills the important aspects of biodegradability and sustainability. Application of vegetable oil-based cutting fluids under MQL techniques are also discussed. Moreover, the potential of palm oil as biodegradable and environmentally friendly natural vegetable oil-based metal-working fluids in MQL are reviewed. [ABSTRACT FROM AUTHOR]

The evolution of materials of cutting tools and their geometry, is currently leading to a technological development of many other sectors linked to machining. It is, therefore, a progress in the construction of machine tools, the machining of new materials, improvement of cutting fluids (lower toxicity and costs related to the maintenance and treatment of used cutting fluids, chemical formulation). Regarding the cutting fluids, international regulations are moving towards eco-elimination or limiting the use of certain molecules for ecological reasons. In addition, the formulation must be adapted as best as possible to the industrial demand, both in terms of performance and costs. The characteristics of nanofluids meet all these requirements and seem to be a promising solution for major problems encountered when using conventional cutting fluids. The present paper reports a literature review emphasizing essentially the investigations performed during the last 2 years. This literature focuses on the use of nano-lubricant in machining processes such as turning, milling and grinding processes. Analyzing the current review, it has been found that the use of nanofluids especially hybrid ones reduces the tool wear, the surface roughness, cutting forces, and heat generation. However, the optimal choice of nanoparticles and their concentrations that suites more the most severe cutting conditions, needs more attention in future works. [ABSTRACT FROM AUTHOR]

Due to their greater workspace and lower cost, industrial robots can provide an alternative solution to CNC machine tools for milling of aerospace parts. However, current machining robots fail to meet the required finishing tolerances (0.1 mm) of the aerospace industry. To improve the accuracy of industrial robots during milling, this paper proposes a new feedback method using an off-the-shelf passive CMM-arm. Unlike laser trackers and optical CMMs, CMM-arms are not susceptible to occlusion or line of sight issues, which may arise due to machining debris or robot movements. In this work, the performance and robustness of a CMM-arm used to guide a robotized machining process in optically challenging conditions are studied. First, the kinematic model of the CMM-arm is developed and the shared workspace between the CMM-arm and a KUKA KR300 Ultra industrial robot is analyzed. This ensures adequate reach of the robot's tool center point (TCP) while the CMM-arm is attached to the machining spindle. The CMM-estimated tool center point is then calculated in real time on an external PC based on the combined kinematic chain of the robot and the CMM-arm. The positioning error of the TCP is determined in real time at a rate of 80 Hz, and the corresponding correction signals are sent to the robot via the Robot Sensor Interface (RSI). Experimental results show over 80% reduction in maximum error during 5-axis milling of aluminum. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to analyze the literature that is currently available and take a glance at minimum quantity lubrication (MQL) with nanofluids (NFs) as viable candidates to improve the efficiency of various milling operations on challenging materials. Design/methodology/approach: The extensive literature review is carried through the existing literature, which shows the effect of various process parameters in the milling operation of challenging materials under NF-MQL conditions. The manuscript also deals with identifying the inferences and research gaps from the literature review. The role and potential of NF-MQL in milling challenging materials are identified in this work. Findings: The conclusion has also derived some recommendations for future study from the prior research, which will be helpful for any further research in this area. Research limitations/implications: This research work is limited to milling operations in challenging materials. Practical implications: NF-MQL applications in milling operations are comparatively underexplored and merit considerable research. The amount of effort industry practitioners put into sustainable manufacturing will surely be greatly reduced by thorough research on the milling of challenging materials under NF-MQL settings. Social implications: MQL system has a great potential to perform well in the experimental endeavor. Despite that fact, majority of the small and medium scale manufacturing industries are still using the conventional flood system for the machining of the workpieces because of the unaffordable initial cost and requirement of expertise involved as compared to the flooded lubrication. This issue might be solved when more works will be accomplished in industries for small as well as medium scale production. Originality/value: These are novel study approaches because there are so many variables that affect cutting efficiency; therefore, more research is required to assess and provide direction for the advancement of hard milling technology. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2023-0010/ [ABSTRACT FROM AUTHOR]

The surface integrity of ultra-high-strength steel has a significant influence on service performance, and cutting fluid plays an important role in maintaining surface integrity in production. In this paper, the surface integrity of ultra-high-strength steel 45CrNiMoVA was investigated under three cutting fluids: HY-103 (micro-emulsion), TRIM E709 (emulsion), and Vasco 7000 (micro-emulsion) from the aspects of cutting force, surface morphology, residual stress, micro hardness, microstructure, etc. The results showed that the changing trend of the cutting forces in three directions is HY-103 > Vasco 7000 > TRIM E709. The TRIM E709 contains the maximum lubricants, which reduce cutting force and Sa roughness, while the Vasco 7000 contains the minimum corrosive elements, which results in the least pitting. Both tangential and axial stresses under cutting fluid are tensile stresses. TRIM E709 and Vasco 7000 are reduced axially by 4.45% and 7.60% relative to HY-103, respectively. The grain refinement layer depths of HY-103, TRIM E709, and Vasco 7000 are 9 μm, 4 μm, and 8 μm, respectively, and TRIM E709 can induce recrystallized grains to grow along {001} of the sample cross section, which results from the lowest cooling rate. This work may provide an innovative control strategy for cutting fluid to improve surface integrity and service performance. [ABSTRACT FROM AUTHOR]

Hole machining of nickel-based alloys has a wide application space in aerospace manufacturing industry, but the high cutting force, high cutting temperature, large plastic deformation, cold work hardening and severe tool wear during the cutting process of nickel-based alloys make them typical difficult-to-machine materials. Therefore, when drilling nickel-based alloys, the selection of cutting parameters is very important. Reasonable cutting parameters will help to control the chip shape and facilitate chip removal. In this paper, the cutting force, cutting temperature, and tool life of high-speed steels in drilling Nickel-based superalloy Inconel 718 was investigated through orthogonal cutting experiments. Then the empirical method of multi-factor line regression was used to establish the empirical models of drilling torque, thrust force, cutting temperature, and tool life of the drills with emulsion as the cutting fluid, and to verify the validity of the established model, and the significance of the regression method is tested to verify the effectiveness of the model. The tool wear morphology and wear mechanisms were examined by scanning electron microscope (SEM) and energy spectrum analysis (EDS). The results revealed that the major drill wear modes incorporate flank wear, peripheral wear, micro-chipping and chipping, and the tool failure mechanisms were comprehensively synergistic interactions among abrasive wear, adhesive wear, and oxidation wear. In addition, the cutting parameters of high-speed steels in drilling Nickel-based superalloy were optimized based on the response surface methodology of equivalent tool life-efficiency, and then the reasonable cutting parameters under the condition of using cutting fluid were recommended. [ABSTRACT FROM AUTHOR]

The paper describes the design and implementation of a cutting fluid monitoring system, as well as the design and development of an algorithm to increase the life of the cutting fluid in the machine tool reservoir. Cutting fluids are the most common type of coolant in machining. During its use, it becomes contaminated and gradually degrades until it needs to be replaced with fresh fluid. To increase its effective service life, its parameters should be monitored at regular intervals, and corrective measures such as topping up the fluid quantity and adding inhibitors and additives should be taken if necessary. For this purpose, a conceptual design of a monitoring device was developed, and a prototype device was subsequently manufactured. The device is designed as a floating probe in the storage tank. Therefore, its shape had to be designed to accommodate multiple sensors, batteries, and electronic components while remaining floating and watertight. The designed prototype was made by additive manufacturing and placed in a cutting fluid while being measured at regular intervals. In the event of non-compliant parameters, the algorithm generated corrective actions, and the machine operator could take the required steps to significantly increase the lifetime of the cutting fluid. [ABSTRACT FROM AUTHOR]

Machining of Inconel-800, a superalloy material that is difficult-to-cut materials, has received the special attention of many scientists worldwide. This paper adopts the advanced and industry-accepted lubrication method that is minimum quantity lubrication technique (MQL) which enhances nanoparticle particles to improve the machinability of Inconel-800 superalloy material and reduce the quantity of conventional cutting fluids. The metamodel namely Radial basis function (RBF) was used for expressing the relationship between cutting velocity, feed per tooth, depth of cut, and corner radius to two quality factors, including cutting force and specific cutting force. A combination of the RBF approximate model and Non-dominated Sorting Genetic Algorithm II (NSGA-II) algorithm was applied to find out optimal global solutions for the multi-objective optimization problem. The results show that this study plays a part in supporting scientists and engineers to understand machining difficult-tocut materials better and minimize waste to the environment towards sustainable and environmentally friendly machining. [ABSTRACT FROM AUTHOR]

Grinding is a widely used process for semi-finishing and finishing of various mechanical components to provide the desired size and accuracy of the product. Grinding wheel is composed of abrasive particles held together firmly in a bond material. The abrasive particles remove material from the workpiece when the grinding wheel is rotated at a high speed with a particular infeed. As a result, extremely high temperature is generated, which produces numerous adverse effects in the grinding performance. To reduce such thermal problems, cutting fluid or coolant is used. In this paper, initially, Analytic Hierarchy Process (AHP) is used for optimization of the grinding performance while grinding under dry and wet environments using three different coolant concentrations (1:80, 1:50 and 1:20) at 30 µm infeed. AHP results show that 1:20 coolant concentration provides the best environment for grinding among the four alternatives in this case. Experimental data are used for Artificial Neural Network (ANN) in MATLAB as input and target data to predict outputs of different coolant concentrations which are not performed experimentally. The output data so obtained are finally used for decision making using AHP, where 1:30 coolant concentration is found to be the optimal coolant concentration. It is also found that the directionality of order of the performance of the coolant with three different concentrations used in actual experiments has remained unchanged in AHP done with 11 alternatives. [ABSTRACT FROM AUTHOR]

Due to growing environmental concerns and economical and social problems in manufacturing sectors, there is a huge demand for the substitution of existing cutting fluids. Further, the cutting fluids selected are expected to reduce the cutting force, improve the surface roughness and also minimize the tool wear during machining operations. Hence, this paper discusses the tribological and morphological behaviour of AISI 316L stainless steel while turning under minimum quantity lubrication (MQL) such as oil–water emulsion, mineral oil, simarouba oil, pongam oil and neem oil based on Taguchi L25 orthogonal array. From the extensive experimentation, it was observed that neem oil MQL with cutting speed of (140, 140, 60 m/min), feed of (0.30, 0.20, 0.10 mm/rev) and depth of cut of (1.0, 1.0, 1.0 mm) resulted in the lowest surface roughness (0.36 µm),cutting force (235.34 N) and tool wear (100.32 microns), respectively. Further, main effects plots and analysis of variance (ANOVA)can be successfully used to identify the optimum process input parameters and their percentage of contribution (P%) on the output parameters during turning of AISI 316L steel under MQL applications. The results clearly indicate that from both an ecological and economical standpoint, neem oil is the most effective lubricant in reducing cutting forces, tool wear and surface roughness during turning of AISI 316L stainless steel under MQL. [ABSTRACT FROM AUTHOR]

This paper deals with experimental investigation on chip formation of machining of Monel K500 and its characteristics are studied. Two different nanocutting fluids namely nanoCuO and nanographenes are used for turning operation and the performance of the two cutting fluids is evaluated and the corresponding responses are recorded for the selection of better cutting fluid. This experiment is carried out with the help of SEM which picturizes the microstructure and surface distribution of the chips. The various output responses like chip thickness, chip compression ratio, and surface roughness are portrayed. The desirable effects on the properties of the machined material obtained by the variation of process parameters like cutting speed, cutting depth, and feed rate are analyzed. Results show that the thickness of chips (corresponding metal removal rate) is reduced considerably by 10–15% and the surface roughness is reduced by 20–30% when nanographene cutting fluids are used. [ABSTRACT FROM AUTHOR]

Superalloy parts place high demands on machined surface integrity and serviceability. In the machining process of superalloys, the cutting fluid is usually used to improve the machining performance. Cutting fluids with cooling and lubrication functions have a relatively large effect on the surface microstructure and residual stress as well. The corrosion damage caused by cutting fluid to the machined surface, during machining and residual, are also worth considering. In this paper, the machining performance of typical binary Ni Cr solid solution, age-hardened, nickel-based superalloy NiCr20TiAl T6, under two commonly used cutting fluids, Blasocut and E709, was analyzed, including cutting performance, surface quality, machining surface corrosion characteristics, and so on. The results showed that the surface residual stress could be improved by adding both cutting fluids compared with the deionized water. Blasocut had better lubrication properties, which could reduce friction and heat production. Pitting holes were found on the polished surface after 45 days with E709 cutting fluid, which was more corrosive than Blasocut. According to this research, a reasonable cutting fluid can be selected to reduce the surface corrosion and improve the service life and performance of parts. [ABSTRACT FROM AUTHOR]

This paper presents a report on cutting fluids utilization and its impacts on workers in machining workshops in Ibadan, Nigeria. The major users of cutting fluids and their workshops were identified. It was found that there are 103 operating metal workshops in Ibadan and these workshops are located within seven local government areas of the city. Out of the total number, 85 are in fabrication, 39 are in crankshaft operations and 32 are engaged in block boring operations. The type and consumption of cutting fluids, coolant delivery techniques, length of use before disposal, disposal methods, and monitoring maintenance were studied. The results indicated that the most used cutting fluid is soluble oil with average total consumption of 402 litres monthly. The pouring of spent cutting fluids on the ground is the most adopted disposal method. Research on occupation exposures to cutting fluids has suggested that machine operators in metal cutting are at high risk of developing cancer, allergenic disorders, and lung diseases. Results obtained also showed that less than 22% of machine operators were aware of occupational hazards. Few of the operators (23%) wore safety devices/clothing, and health and safety standards were neither practiced nor enforced. [ABSTRACT FROM AUTHOR]

A study has been conducted to find out the rheological properties of h-BN nano cutting fluid and then its effects have been analyzed on the machinability of Inconel 625. It is to be noted that addition of nanoparticles with improved rheological behavior helps to enhance the anti-wear and anti-frictional properties of cutting fluid. Hexagonal boron nitride (h-BN) nanoparticles are environmentally safe, chemically inert, and lubricious in nature and hence preparation of BN nano cutting fluid is a reliable option for machining with MQL technique in machining of difficult to cut material like Inconel-625. This paper includes preparation of BN-nano cutting fluid with analysis of its rheological properties and effect on machining of Inconel 625 with h-Bn nano fluid assisted MQL. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of the type of movement on the tribological properties of an AlTiN coating applied to a disc made of HS6-5-2C steel. Tribological tests were carried out with a tribometer operating on a ball-disc friction apparatus moving in to-and-from as well as in rotary motion. The tests were carried out under technically dry friction conditions, subject to the application of a cutting fluid used during machining in grinding, turning, milling, drilling and cutting processes. A scanning microscope was used to observe the morphology of the surface, the morphology of the AlTiN coating, and to determine its chemical composition and assess wear mechanisms. The topography of the surface was analysed before and after carrying out the friction and wear tests using a confocal microscope with interferometric mode. The results of the provided tests indicate that the cutting fluid used in the tests reduced the coefficient of friction in both rotary and the sliding -- reciprocating motion about 75% and 65% respectively. It has also contributed to a reduction in linear wear in the sliding -- reciprocating motion about 22%. In case of rotary motion, higher values of linear wear about 40% were recorded, due to wear of the counterspecimen. [ABSTRACT FROM AUTHOR]