The Experts below are selected from a list of 6690 Experts worldwide ranked by ideXlab platform
Mohammed Nouari - One of the best experts on this subject based on the ideXlab platform.
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finite element modelling of the thermo mechanical behavior of coatings under extreme contact loading in Dry Machining
Surface & Coatings Technology, 2011Co-Authors: F Kone, C Czarnota, Badis Haddag, Mohammed NouariAbstract:Abstract During metal cutting processes, intensive friction and high temperature generated at the tool chip interface affect the cutting zone of the tool, by inducing damage and wear. To improve the cutting tool's life, thin hard coatings, synthesized by physical or chemical vapor deposition (PVD or CVD) techniques, are often used as protective layers. In this work, numerical/theoretical analysis of Dry Machining has been performed to study the impact of different coating layers on the Machining process. Four cases are considered: an uncoated tool made of tungsten carbide (WC–Co) and coated tungsten carbides in three different configurations. The first one is made of one layer namely TiN, the second one (hypothetical carbide insert) is composed of two layers (Al 2 O 3 and TiN), and the last one has three layers (TiCN, Al 2 O 3 and TiN). The workpiece material is an AISI 316L stainless steel. All cutting conditions are fixed in order to highlight the effect of coatings independently from others influencing parameters. The analysis has shown the impact of the different configurations of coatings on the temperature level inside the tool and on its surface, on the pressure and also on the cutting and feed forces.
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Damage modes of straight tungsten carbide in Dry Machining of titanium alloy TA6V
Journal De Physique Iv, 2006Co-Authors: Madalina Calamaz, D. Géhin, Mohammed Nouari, Franck GirotAbstract:In the present study, Dry Machining of the titanium alloy TA6V with cemented tungsten carbide tools is tested. The main objective is to analyse the feasibility of the Dry Machining process on the difficult to cut materials as titanium alloys. The wide accepted tool material for Machining this kind of materials i.e. straight tungsten carbide (WC-Co), was initially chosen. During the trials, the tool was rigidly mounted on tool holder with rake angles of 0°, 15° and 30°. Three cutting speeds (15, 30 and 60 m/min) and three feeds (0.1, 0.2 and 0.3 mm) were used. In order to avoid the shock at the beginning of the cutting operation, the workpiece was prepared by carrying out a chamfer. All inserts have achieved 5 passes (1 pass = 1 m). During the trials the cutting force components were measured using a piezoelectric dynamometer. Scanning electron microscope (SEM) supported by energy dispersive x-ray (EDX) and optical profilometer were investigated in the detailed analysis of tool wear. The correlation between the evolution of cutting forces, the tool damage modes and the workpiece roughness show the influence of the cutting parameters and the insert geometry on the tool wear and on the quality of the finished surface when Dry Machining TA6V.
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Wear behaviour of cemented carbide tools in Dry Machining of aluminium alloy
Wear, 2005Co-Authors: Georg List, D. Géhin, D. Géhin, J. P. Manaud, S Gomez, Mohammed Nouari, Yann Le PetitcorpsAbstract:Several causes of tool wear have been investigated in Dry Machining of aluminium alloy with cemented carbide insert; some of the most important are: adhesion and diffusion. The formation of built-up edge (BUE) and adhesive layer on the tool rake face degrades on the one hand, the shape and efficiency of cutting tool and on the other hand, the surface quality and dimensional accuracy of the finished product. This paper describes tool wear mechanisms in Dry Machining of a usual aluminium-copper alloy (2024) with an uncoated cemented carbide tool (WC-Co). Orthogonal cutting tests were performed using an instrumented planer machine. The morphology of chips, cutting forces and contact lengths were analyzed for several cutting conditions. The tool-chip interface temperature and the average pressure were calculated by conducting calibration-cutting experiments in conjunction with FEM simulations. This allowed to define the contact parameters associated with different cutting conditions on the tool rake face. High-speed camera movies (CCD), white light interferometry, scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometer (EDS) and Auger electron spectroscopy (AES) were investigated to show the development of the built-up edge and the adhesive layer on the tool rake face during Machining process. The results confirmed that the wear mechanisms involve the activation of the chemical and the diffusional phenomenon. © 2004 Elsevier B.V. All rights reserved.
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Wear behaviour of cemented carbide tools in Dry Machining of aluminium alloy
Wear, 2005Co-Authors: Georg List, D. Géhin, J. P. Manaud, Yann Le Petitcorps, S Gomez, Mohammed Nouari, F. GirotAbstract:Several causes of tool wear have been investigated in Dry Machining of aluminium alloy with cemented carbide insert; some of the most important are: adhesion and diffusion. The formation of built-up edge (BUE) and adhesive layer on the tool rake face degrades on the one hand, the shape and efficiency of cutting tool and on the other hand, the surface quality and dimensional accuracy of the finished product. This paper describes tool wear mechanisms in Dry Machining of a usual aluminium–copper alloy (2024) with an uncoated cemented carbide tool (WC–Co). Orthogonal cutting tests were performed using an instrumented planer machine. The morphology of chips, cutting forces and contact lengths were analyzed for several cutting conditions. The tool–chip interface temperature and the average pressure were calculated by conducting calibration–cutting experiments in conjunction with FEM simulations. This allowed to define the contact parameters associated with different cutting conditions on the tool rake face. High-speed camera movies (CCD), white light interferometry, scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometer (EDS) and Auger electron spectroscopy (AES) were investigated to show the development of the built-up edge and the adhesive layer on the tool rake face during Machining process. The results confirmed that the wear mechanisms involve the activation of the chemical and the diffusional phenomenon
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experimental analysis and optimisation of tool wear in Dry Machining of aluminium alloys
Wear, 2003Co-Authors: Mohammed Nouari, Georg List, F. Girot, Dominique CoupardAbstract:Abstract In Machining, coolants and lubricants improve machinability, increase productivity by reducing the tool wear and extend the tool life. However, the use of cutting fluids in metal working operations may seriously degrade the quality of the environment. Consequently, many governments recommend the manufacturers to reduce the volume and the toxicity of their cutting fluids. Up to now, Dry Machining has remained a real challenge for the industrial world, particularly in aerospace engineering. The experimental approach taken in this study resulted in the development of both optimised tool geometry and optimised cutting conditions for drilling aluminium alloys without the need for lubrication. The experimental investigations were carried out with WC–Co cemented carbide drills. The use of diamond as coating material allowed to extend the tool life. The combination of the optimised tool geometry and the cutting conditions entails a high surface quality, a good dimensional accuracy of the machined material and ensures a long lifetime to the drill. Besides, a numerical calculation with Third Wave AdvantEdge™ finite element software was used to predict the tool–chip interface temperature, which is the major parameter inducing tool wear in Dry drilling.
Dominique Coupard - One of the best experts on this subject based on the ideXlab platform.
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Chip/Tool Interaction during Dry Machining of the TA6V Alloy
Advanced Materials Research, 2012Co-Authors: Madalina Calamaz, M. E. Gutierrez‐orrantia, Dominique Coupard, J. BegaAbstract:During chip formation, material is subjected to high deformations and high strain rates which generate high pressures and temperatures. Cutting fluids have an important role but produce many constraints: cleaning of parts, environment quality degradation, cost increase, diseases as identified by the European Agency for Safety and Health at Work. Dry Machining is one of the future challenges although its implementation remains delicate, in particular for TiAl6V alloy. This paper aims at correlating the contact conditions at the tool/chip interface with the tool wear to understand the wear mechanisms of carbide tools in Dry Machining. Numerical simulations, experimentally validated, allow pointing out that the temperature distribution at the tool/chip interface depends on chip type (continuous, serrated). For continuous chips, the temperature is fairly uniform and stationary throughout the interface. For segmented chips, a cold zone between two temperature peaks is observed and moves along the tool rake face during the formation of a chip segment. The evolution of the normal stress at the interface is similar for both types of chips at the beginning of the localization phenomenon. These pressure and temperature fields allow the titanium to diffuse into the tungsten carbide and form the mixed carbide (Ti, W)C, which is very sensitive to oxidation above 500°C. This could explain the attrition of the tool, due to the brittleness of the oxycarbides. Contact conditions and tool wear are finally correlated.
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numerical simulation of titanium alloy Dry Machining with a strain softening constitutive law
Machining Science and Technology, 2010Co-Authors: Madalina Calamaz, Dominique Coupard, Franck GirotAbstract:In this study, the commercial finite element software FORGE2005®, able to solve complex thermo-mechanical problems is used to model titanium alloy Dry Machining. One of the main Machining characteristics of titanium alloys is to produce a special chip morphology named “saw-tooth chip” or serrated chip for a wide range of cutting speeds and feeds. The mechanism of saw-tooth chip formation is still not completely understood. Among the two theories about its formation, this study assumes that chip segmentation is only induced by adiabatic shear band formation and thus no material failure occurs in the primary shear zone. Based on the assumption of material strain softening, a new material law was developed. The aim of this study is to analyze the newly developed model's capacity to correctly simulate the Machining process. The model validation is based on the comparison of experimental and simulated results, such as chip formation, global chip morphology, cutting forces and geometrical chip characteristics. ...
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Numerical simulation of titanium alloy Dry Machining with a strain softening constitutive law
Machining Science and Technology, 2010Co-Authors: Madalina Calamaz, Dominique Coupard, Franck GirotAbstract:In this study, the commercial finite element software FORGE2005, able to solve complex thermo-mechanical problems is used to model titanium alloy Dry Machining. One of the main Machining characteristics of titanium alloys is to produce a special chip morphology named "saw-tooth chip" or serrated chip for a wide range of cutting speeds and feeds. The mechanism of saw-tooth chip formation is still not completely understood. Among the two theories about its formation, this study assumes that chip segmentation is only induced by adiabatic shear band formation and thus no material failure occurs in the primary shear zone. Based on the assumption of material strain softening, a new material law was developed. The aim of this study is to analyze the newly developed model's capacity to correctly simulate the Machining process. The model validation is based on the comparison of experimental and simulated results, such as chip formation, global chip morphology, cutting forces and geometrical chip characteristics. A good correlation was found between the experimental and numerical results, especially for cutting speeds generating low tool wear.
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experimental analysis and optimisation of tool wear in Dry Machining of aluminium alloys
Wear, 2003Co-Authors: Mohammed Nouari, Georg List, F. Girot, Dominique CoupardAbstract:Abstract In Machining, coolants and lubricants improve machinability, increase productivity by reducing the tool wear and extend the tool life. However, the use of cutting fluids in metal working operations may seriously degrade the quality of the environment. Consequently, many governments recommend the manufacturers to reduce the volume and the toxicity of their cutting fluids. Up to now, Dry Machining has remained a real challenge for the industrial world, particularly in aerospace engineering. The experimental approach taken in this study resulted in the development of both optimised tool geometry and optimised cutting conditions for drilling aluminium alloys without the need for lubrication. The experimental investigations were carried out with WC–Co cemented carbide drills. The use of diamond as coating material allowed to extend the tool life. The combination of the optimised tool geometry and the cutting conditions entails a high surface quality, a good dimensional accuracy of the machined material and ensures a long lifetime to the drill. Besides, a numerical calculation with Third Wave AdvantEdge™ finite element software was used to predict the tool–chip interface temperature, which is the major parameter inducing tool wear in Dry drilling.
Christina Berger - One of the best experts on this subject based on the ideXlab platform.
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Dry Machining Using CrAlYN Coated Carbides
Plasma Processes and Polymers, 2007Co-Authors: Eberhard Abele, Burkhard Schramm, Christina Berger, Herbert ScheererAbstract:The current study discusses the influence of yttrium content of magnetron sputtered chromium-based coatings on the wear behavior in Dry Machining of steel and aluminum alloy. Both tribological tests and practical wear experiments in Dry turning and drilling were performed. The characterization of the coatings includes the measurement of thickness and hardness, as well as a detailed analysis of the coating composition. Dry turning and drilling operations were performed in order to evaluate the wear resistance of CrxAlyN and CrxAlyYzN during practical applications.
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effects of the chromium to aluminum content on the tribology in Dry Machining using cr al n coated tools
Surface & Coatings Technology, 2005Co-Authors: Herbert Scheerer, Eberhard Abele, Burkhard Schramm, Holger Hoche, Erhard Broszeit, Christina BergerAbstract:Abstract The present study investigates the potentials of newly developed (Cr,Al)N coatings compared to uncoated tools. The aim of using chromium-based coatings is to create a thermal barrier and thus redirecting the heat from work piece and tool into the chip. Due to their high resistance for oxidation, CrxAlyN coatings with different chromium to aluminum contents were deposited onto indexed carbide inserts. In order to find improved coatings for Dry Machining operations both tribological and wear tests were performed. These tests include fundamental properties such as thickness, hardness, and critical load. With Glow Discharge Optical Emission Spectroscopy (GDOES) depth profile analyses were conducted. In reciprocating sliding tests, using an SRV III apparatus from Optimol, friction and wear has been studied in a ball-on-disc arrangement. Longitudinal turning tests were performed to characterize the Dry Machining characteristics. As described above, the coatings' characteristics such as hardness and critical load as well as the results from the reciprocating sliding test correlate with the Dry turning tests. The best coatings in the tests have similar chromium and aluminum contents in the region of 15 at.%, the nitrogen content was about 60 at.%, respectively. An increase of the Cr content in the coating deteriorates the performance of the coated carbide beneath the level of the uncoated tool. An adhesion phenomenon that leads to a formation of an adherent layer on the cutting edge is attributed to the completely unlimited mutual solid solubility of Cr and Fe at a temperature beyond 800 °C.
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Tribological properties and Dry Machining characteristics of PVD-coated carbide inserts
Surface & Coatings Technology, 2004Co-Authors: Burkhard Schramm, Eberhard Abele, Herbert Scheerer, Holger Hoche, Erhard Broszeit, Christina BergerAbstract:Abstract Tools for cutting operation are subject to very high abrasive, adhesive, and thermal loads. Process security and preparation quality as well as a sufficiently high tool life demand for the development of hard coatings with reduced seizure tendency, high hot hardness, and increased wear resistance especially under Dry Machining conditions. TiAlN coatings are the state-of-the-art coatings for Machining operations. Hard materials on chromium basis like CrN or CrAlN are preferably used for bending and stamping tools. Thus, these coatings could have a high potential in Machining operations. The aim of using chromium-based coatings is to redirect the heat from the workpiece and tool into the chip, thus acting as a thermal barrier. Due to their high oxidation resistance, CrN and Cr x Al y N coatings were deposited on WC/Co inserts. In order to find improved coatings for Dry Machining operations, mechanical characterizations and turning tests were performed. The characterization of the coatings includes fundamental properties such as thickness, hardness, and critical load. With Glow Discharge Optical Emission Spectroscopy (GDOES), depth profile analyses were executed. SEM analyses supplemented the picture of the scratch tests. Turning operations were performed in model tests to characterize the Dry Machining characteristics. The wear properties of CrN and Cr x Al y N coatings were compared with industrially coated (Ti,Al)N carbide inserts. Calculations of the friction coefficient supplemented the tests.
Herbert Scheerer - One of the best experts on this subject based on the ideXlab platform.
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Dry Machining Using CrAlYN Coated Carbides
Plasma Processes and Polymers, 2007Co-Authors: Eberhard Abele, Burkhard Schramm, Christina Berger, Herbert ScheererAbstract:The current study discusses the influence of yttrium content of magnetron sputtered chromium-based coatings on the wear behavior in Dry Machining of steel and aluminum alloy. Both tribological tests and practical wear experiments in Dry turning and drilling were performed. The characterization of the coatings includes the measurement of thickness and hardness, as well as a detailed analysis of the coating composition. Dry turning and drilling operations were performed in order to evaluate the wear resistance of CrxAlyN and CrxAlyYzN during practical applications.
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effects of the chromium to aluminum content on the tribology in Dry Machining using cr al n coated tools
Surface & Coatings Technology, 2005Co-Authors: Herbert Scheerer, Eberhard Abele, Burkhard Schramm, Holger Hoche, Erhard Broszeit, Christina BergerAbstract:Abstract The present study investigates the potentials of newly developed (Cr,Al)N coatings compared to uncoated tools. The aim of using chromium-based coatings is to create a thermal barrier and thus redirecting the heat from work piece and tool into the chip. Due to their high resistance for oxidation, CrxAlyN coatings with different chromium to aluminum contents were deposited onto indexed carbide inserts. In order to find improved coatings for Dry Machining operations both tribological and wear tests were performed. These tests include fundamental properties such as thickness, hardness, and critical load. With Glow Discharge Optical Emission Spectroscopy (GDOES) depth profile analyses were conducted. In reciprocating sliding tests, using an SRV III apparatus from Optimol, friction and wear has been studied in a ball-on-disc arrangement. Longitudinal turning tests were performed to characterize the Dry Machining characteristics. As described above, the coatings' characteristics such as hardness and critical load as well as the results from the reciprocating sliding test correlate with the Dry turning tests. The best coatings in the tests have similar chromium and aluminum contents in the region of 15 at.%, the nitrogen content was about 60 at.%, respectively. An increase of the Cr content in the coating deteriorates the performance of the coated carbide beneath the level of the uncoated tool. An adhesion phenomenon that leads to a formation of an adherent layer on the cutting edge is attributed to the completely unlimited mutual solid solubility of Cr and Fe at a temperature beyond 800 °C.
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Tribological properties and Dry Machining characteristics of PVD-coated carbide inserts
Surface & Coatings Technology, 2004Co-Authors: Burkhard Schramm, Eberhard Abele, Herbert Scheerer, Holger Hoche, Erhard Broszeit, Christina BergerAbstract:Abstract Tools for cutting operation are subject to very high abrasive, adhesive, and thermal loads. Process security and preparation quality as well as a sufficiently high tool life demand for the development of hard coatings with reduced seizure tendency, high hot hardness, and increased wear resistance especially under Dry Machining conditions. TiAlN coatings are the state-of-the-art coatings for Machining operations. Hard materials on chromium basis like CrN or CrAlN are preferably used for bending and stamping tools. Thus, these coatings could have a high potential in Machining operations. The aim of using chromium-based coatings is to redirect the heat from the workpiece and tool into the chip, thus acting as a thermal barrier. Due to their high oxidation resistance, CrN and Cr x Al y N coatings were deposited on WC/Co inserts. In order to find improved coatings for Dry Machining operations, mechanical characterizations and turning tests were performed. The characterization of the coatings includes fundamental properties such as thickness, hardness, and critical load. With Glow Discharge Optical Emission Spectroscopy (GDOES), depth profile analyses were executed. SEM analyses supplemented the picture of the scratch tests. Turning operations were performed in model tests to characterize the Dry Machining characteristics. The wear properties of CrN and Cr x Al y N coatings were compared with industrially coated (Ti,Al)N carbide inserts. Calculations of the friction coefficient supplemented the tests.
Prabir Sarkar - One of the best experts on this subject based on the ideXlab platform.
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Effects of surface texture parameters of cutting tools on friction conditions at tool-chip interface during Dry Machining of AISI 1045 steel
Procedia Manufacturing, 2019Co-Authors: Sagar Dhage, A. D. Jayal, Prabir SarkarAbstract:Abstract Dry Machining is one of the essential steps towards achieving sustainable manufacturing processes. Sustainable Dry Machining can be further enhanced by using surface textured cutting tools where the micro-capillary networks on cutting tool surfaces are exploited for tribological benefit in the absence of cutting fluids. This paper presents the results of an experimental study in which rake surfaces of uncoated carbide cutting tools are textured at different levels, and orthogonal Machining is performed on AISI 1045 steel under Dry Machining condition. The results show that skewness, kurtosis, and other surface texture parameters on the rake surface significantly influence the Machining forces via altering friction conditions at the tool-chip interface. Further, the orientation of the cutting tool’s surface texture pattern has a strong effect on the capability of the surface micro-capillary network to allow atmospheric air, which must serve as a lubricant in Dry cutting, to access portions of the tool-chip contact zone.
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Dry Machining: A step towards sustainable Machining – Challenges and future directions
Journal of Cleaner Production, 2017Co-Authors: Gyanendra Singh Goindi, Prabir SarkarAbstract:Abstract Manufacturing activity is a major consumer of energy and natural resources. In Machining process, a large amount of heat is produced whose removal requires the use of suitable cooling agents or cutting fluids, which are a major source of waste generation and environmental damage. To eliminate hazardous cutting fluids during Machining operations, researchers have tried Machining components without applying cutting fluids, which is also known as Dry Machining. Dry Machining, however, has many challenges. The aim of this paper is to present a systematic, critical, and comprehensive review of all aspects of Dry Machining including the sustainability aspects of Machining, especially focusing on three research objectives. For the first research objective, we identify the areas where Dry Machining has been successfully adopted and where it has not been possible to do so. The problems and challenges arising out of Dry Machining and their impact on the life of the cutting tool, workpiece geometrical accuracies, the surface integrity of the workpiece, and the issues related to machinability of materials as well as Machining operation specific issues have also been identified. For the second aim of this review, we report the research work carried out and various alternative solutions provided by the researchers in the area of Dry Machining, till the date. The period taken into consideration for the survey is the last 15 years, from the year the 2000–2015, with particular attention to the published work during the last five years. The research in this direction has been focused primarily on the application of advanced tool materials and coatings, which are resistant to high cutting temperatures frequently encountered in Dry cutting, tool geometry modifications, laser or modulation-assisted Machining, and minimum quantity lubrication Machining. The application of this research work to carry out successful Dry Machining of various ferrous and non-ferrous workpiece materials and cutting in different Machining operations are also discussed. The sustainability assessment of different Machining processes is also discussed. For the third objective, we find gaps in the current knowledge and suggest some directions for further work to make Dry Machining more sustainable, profitable, and adaptable to product manufacturers.
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Dry Machining a step towards sustainable Machining challenges and future directions
Journal of Cleaner Production, 2017Co-Authors: Gyanendra Singh Goindi, Prabir SarkarAbstract:Abstract Manufacturing activity is a major consumer of energy and natural resources. In Machining process, a large amount of heat is produced whose removal requires the use of suitable cooling agents or cutting fluids, which are a major source of waste generation and environmental damage. To eliminate hazardous cutting fluids during Machining operations, researchers have tried Machining components without applying cutting fluids, which is also known as Dry Machining. Dry Machining, however, has many challenges. The aim of this paper is to present a systematic, critical, and comprehensive review of all aspects of Dry Machining including the sustainability aspects of Machining, especially focusing on three research objectives. For the first research objective, we identify the areas where Dry Machining has been successfully adopted and where it has not been possible to do so. The problems and challenges arising out of Dry Machining and their impact on the life of the cutting tool, workpiece geometrical accuracies, the surface integrity of the workpiece, and the issues related to machinability of materials as well as Machining operation specific issues have also been identified. For the second aim of this review, we report the research work carried out and various alternative solutions provided by the researchers in the area of Dry Machining, till the date. The period taken into consideration for the survey is the last 15 years, from the year the 2000–2015, with particular attention to the published work during the last five years. The research in this direction has been focused primarily on the application of advanced tool materials and coatings, which are resistant to high cutting temperatures frequently encountered in Dry cutting, tool geometry modifications, laser or modulation-assisted Machining, and minimum quantity lubrication Machining. The application of this research work to carry out successful Dry Machining of various ferrous and non-ferrous workpiece materials and cutting in different Machining operations are also discussed. The sustainability assessment of different Machining processes is also discussed. For the third objective, we find gaps in the current knowledge and suggest some directions for further work to make Dry Machining more sustainable, profitable, and adaptable to product manufacturers.
