The research and application of high speed metal cutting (HSMC) is aimed at achieving higher productivity and improved surface quality. This paper reviews the advancements in HSMC with a focus on the ...material removal mechanism and machined surface integrity without considering the effect of cutting dynamics on the machining process. In addition, the variation of cutting force and cutting temperature as well as the tool wear behavior during HSMC are summarized. Through comparing with conventional machining (or called as normal speed machining), the advantages of HSMC are elaborated from the aspects of high material removal rate, good finished surface quality (except surface residual stress), low cutting force, and low cutting temperature. Meanwhile, the shortcomings of HSMC are presented from the aspects of high tool wear rate and tensile residual stress on finished surface. The variation of material dynamic properties at high cutting speeds is the underlying mechanism responsible for the transition of chip morphology and material removal mechanism. Less surface defects and lower surface roughness can be obtained at a specific range of high cutting speeds, which depends on the workpiece material and cutting conditions. The thorough review on pros and cons of HSMC can help to effectively utilize its advantages and circumvent its shortcomings. Furthermore, the challenges for advancing and future research directions of HSMC are highlighted. Particularly, to reveal the relationships among inherent attributes of workpiece materials, processing parameters during HSMC, and evolution of machined surface properties will be a potential breakthrough direction. Although the influence of cutting speed on the material removal mechanism and surface integrity has been studied extensively, it still requires more detailed investigations in the future with continuous increase in cutting speed and emergence of new engineering materials in industries.
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•Material removal mechanism of HSM is summarized considering material dynamic properties.•Machined surface integrity is discussed with emphasis on metallurgical alterations.•Cutting force/temperature and tool wear behavior in HSM are summarized.•The pros and cons of HSM are elaborated to guide its industrial application.•Challenges for further development of HSM and future directions are highlighted.
The Special Issue Machining—Recent Advances, Applications and Challenges is intended as a humble collection of some of the hottest topics in machining. The manufacturing industry is a varying and ...challenging environment where new advances emerge from one day to another. In recent years, new manufacturing procedures have retained increasing attention from the industrial and scientific community. However, machining still remains the key operation to achieve high productivity and precision for high-added value parts. Continuous research is performed, and new ideas are constantly considered. This Special Issue summarizes selected high-quality papers which were submitted, peer-reviewed, and recommended by experts. It covers some (but not only) of the following topics:
High performance operations for difficult-to-cut alloys, wrought and cast materials, light alloys, ceramics, etc.;
Cutting tools, grades, substrates and coatings. Wear damage;
Advanced cooling in machining: Minimum quantity of lubricant, dry or cryogenics;
Modelling, focused on the reduction of risks, the process outcome, and to maintain surface integrity;
Vibration problems in machines: Active and passive/predictive methods, sources, diagnosis and avoidance;
Influence of machining in new concepts of machine–tool, and machine static and dynamic behaviors;
Machinability of new composites, brittle and emerging materials;
Assisted machining processes by high-pressure, laser, US, and others;
Introduction of new analytics and decision making into machining programming.
We wish to thank the reviewers and staff from Materials for their comments, advice, suggestions and invaluable support during the development of this Special Issue.
The cutting fluid is significant in any metal cutting operation, for cooling the cutting tool and the surface of the workpiece, by lubricating the tool-workpiece interface and removing chips from the ...cutting zone. Recently, many researchers have been focusing on minimum quantity lubrication (MQL) among the numerous methods existing on the application of the coolant as it reduces the usage of coolant by spurting a mixture of compressed air and cutting fluid in an improved way instead of flood cooling. The MQL method has been demonstrated to be appropriate as it fulfills the necessities of ‘green’ machining. In the current study, firstly, various lubrication methods were introduced which are used in machining processes, and then, basic machining processes used in manufacturing industries such as grinding, milling, turning, and drilling have been discussed. The comprehensive review of various nanofluids (NFs) used as lubricants by different researchers for machining process is presented. Furthermore, some cases of utilizing NFs in machining operations have been reported briefly in a table. Based on the studies, it can be concluded that utilizing NFs as coolant and lubricant lead to lower tool temperature, tool wear, higher surface quality, and less environmental dangers. However, the high cost of nanoparticles, need for devices, clustering, and sediment are still challenges for the NF applications in metalworking operations. At last, the article identifies the opportunities for using NFs as lubricants in the future. It should be stated that this work offers a clear guideline for utilizing MQL and MQL-nanofluid approaches in machining processes. This guideline shows the physical, tribological, and heat transfer mechanisms associated with employing such cooling/lubrication approaches and their effects on different machining quality characteristics such as tool wear, surface integrity, and cutting forces.
As widely reported in the literature, the micro-texturing technique has a significant potential to improve the performance of cutting tools by reducing cutting forces, friction, temperature, and tool ...wear, and further, by improving tribological behavior at the tool-chip and tool-workpiece interface. However, it is also known that the effects of textures on the cutting tool surface strongly depend on the texture geometry and dimensions, and that the application of indiscriminate surface textures to cutting tools often results in adverse effects on cutting performance, indicating that an improved understanding of surface phenomena is required to further develop textured cutting tools. This paper summarizes recent advances in tool surface texturing in metal cutting fields, and continues to describe how the textured surface of a cutting tool influences the deformation fields of the workpiece material, including both primary and secondary shear zones, by means of direct in-situ observation using particle image velocimetry analysis to understand the behavior in the vicinity of the textured surfaces during the cutting process. The experimental results with the textured cutting tool reveal that the effect of the grooved rake face on the cutting force differs depending on the relative position of the microgroove with respect to the undeformed chip thickness. The friction condition and where the texture is located determine the performance of the surface texture. The link between the interface friction and chip flow mode is discussed, and it is demonstrated that surface textures can alter the chip flow mode from a segmented flow with redundant deformation to a steadier homogeneous flow with lower cutting energy.
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•In-situ observation reveals how surface textures influence the deformation field.•Severe interface friction results in redundant deformation in primary shear zone.•Textured rake face significantly facilitates chip flow at the tool-chip interface.•The effect of texture depends on texture location relative to the tool-chip contact.•The effect of the texture is related to friction conditions at the tool-chip interface.
The machining performance and mechanisms of straight-nosed cutting tools in the single-point diamond turning (SPDT) of curved Zerodur optics are analysed and experimentally investigated. Analyses ...into the SPDT processes of convex spherical Zerodur samples have shown that using straight-nosed cutting tools can significantly reduce the cut thickness for facilitating the ductile-mode material removal while increasing the width of cut compared with the conventional round-nosed cutting tools. Calculations have also shown that lower cutting force intensities would be acting on the straight cutting edges than the round ones, which can in turn contribute to decreasing the heat flux density into the cutting tool, and is thus expected to reduce the thermal-induced cutting tool wear. To verify these, SPDT tests of spherical Zerodur samples were carried out, where a reduction of the machined surface roughness from Ra 173 nm to 15 nm was achieved by using the straight-nosed cutting tools, and a 96% area ratio of ductile-mode cutting was obtainable with very slight damage marks left on the machined surface. It has been further found that the straight-nosed cutting tools suffered less flank wear, as well as less bluntness and recession of the cutting edge. The mean cutting and thrust forces acting on per unit length of the cutting edge were found to be reduced, which agrees well with the prior analytical results, and is believed as evidence for the reduction of cutting power required for each unit cutting edge area for enhancing the resistance to cutting tool wear.
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●This work reports the mechanisms behind which using straight-nosed cutting tools improves the machining performance in single-point diamond turning of curved Zerodur optics.●A 96% area ratio of ductile-mode cutting is obtainable in single-point diamond turning of spherical Zerodur samples by using straight-nosed cutting tools for a nano-scale surface finish.●Using the straight-nosed cutting tools is effective in reducing the recession and bluntness of tool cutting edge, as well as work adhesion and flank wear for extending the cutting tool life.●The straight-shaped cutting edge reduces the cutting force intensities applied on the cutting edge and heat flux density into the cutting tool for the reduction of cutting tool wear.
Machining is an indispensable manufacturing process for a wide range of engineering materials, such as metals, ceramics, and composite materials, in which the tool wear is a serious problem, which ...affects not only the costs and productivity but also the quality of the machined components. Thus, the modification of the cutting tool surface by application of textures on their surfaces is proposed as a very promising method for improving tool life. Surface texturing is a relatively new surface engineering technology, where microscale or nanoscale surface textures are generated on the cutting tool through a variety of techniques in order to improve tribological properties of cutting tool surfaces by reducing the coefficient of friction and increasing wear resistance. In this paper, the studies carried out to date on the texturing of ceramic and superhard cutting tools have been reviewed. Furthermore, the most common methods for creating textures on the surfaces of different materials have been summarized. Moreover, the parameters that are generally used in surface texturing, which should be indicated in all future studies of textured cutting tools in order to have a better understanding of its effects in the cutting process, are described. In addition, this paper proposes a way in which to classify the texture surfaces used in the cutting tools according to their geometric parameters. This paper highlights the effect of ceramic and superhard textured cutting tools in improving the machining performance of difficult-to-cut materials, such as coefficient of friction, tool wear, cutting forces, cutting temperature, and machined workpiece roughness. Finally, a conclusion of the analyzed papers is given.
•Tool coating effects on cutting temperature in metal cutting process are reviewed.•Factors influencing on cutting temperature with coated tools are analyzed.•Measurements and determination ...approaches of the influencing factors are illustrated.•Predictive modelling methods for cutting temperature with coated tool are discussed.•Measurement technologies on cutting temperature with coated tool are illustrated.
Nowadays, coatings have been widely deposited on cutting tool inserts due to their superior wear resistant and thermal barrier effect in metal manufacturing industry. Tool coatings avoid the direct contact between the workpiece and tool substrate, thus affecting the cutting temperature and machining performance compared with uncoated tools. This article aims to review the tool coating effects on cutting temperature during metal cutting process. Firstly, the factors influencing on cutting temperature with coated tools are analyzed including the geometric factors, thermal physical properties, coated tool-chip contact characteristics and coating-substrate diffusion layer. The determination approaches of these influencing factors are illustrated. Secondly, the predictive modelling for cutting temperature with coated tool including analytical thermal models and simulation methods (finite element method-FEM, finite difference method-FDM, boundary element method-BEM) are discussed, respectively. Thirdly, the experimental measurements on cutting temperature with coated tool are reviewed and analyzed. The possible perspectives of future work for investigating the tool coating effects on cutting temperature are proposed. This review would help to obtain knowledge of tool coating effects on cutting temperature with coated tools, thus for better selection and design suitable tool coatings by decreasing cutting temperature.
Tungsten alloy has excellent performance and has been widely used in military, aerospace and nuclear energy, and other cutting-edge industries. However, tungsten alloy has large hardness, high ...strength, and poor plastic deformation ability, which resulted in high cutting force and serious tool wear during the cutting process, leading to low surface quality of the workpiece after molding. Therefore, it is of great significance to strengthen the research on tungsten alloy cutting technology to promote the development of tungsten alloy application. Firstly, the research progress of tungsten alloy cutting process technology has been systematically reviewed, and the current status of cutting parameters optimization, new cutting methods and devices, and cutting fluid technology have been emphatically reviewed. Secondly, the types of tungsten alloy cutting tools, the relevant tool micro-texture, and tool coatings technology have been briefly described, and the composite cutting technology such as cryogenic cutting, electroplastically assisted cutting, and ultrasonic vibration assisted cutting and the effect of cutting performance prediction technology on tungsten alloy machining performance have been summarized. Finally, the development prospect of tungsten alloy cutting technology has been prospected.
This paper contributes to broadening the knowledge regarding cutting tool wear in the finish turning operations of nickel-chromium-based superalloy Inconel 718. Three cutting tools coated with heat ...isolating TiAlN/AlTiN layers with different stoichiometry ratios recommended as specially designed cutting tools for aerospace industry applications are tested. The primary comparison of tool wear resistance was based on the wear curves related to the cutting time and the removed material volume. The basic study include the modeling of wear progress and examining tool wear scars based on SME images and EDX analysis. In addition, tool wear progress was recorded along with continuous measurements of cutting forces and determination of relevant amount of the specific cutting energy and the friction coefficient.
•Tool wear of AlTiN and TIAlN coated cutting tool inserts when turning Inconel 718 superalloy was investigated.•Tool wear curves as functions of the cutting time and removed material volume are presented.•Modelling of tool wear in terms of the cutting time and removed material volume is proposed.•Tool wear mechanisms concentrated on the tool corner related to finish turning operations are explored and discussed.•The relationships between tool wear and cutting force components and specific cutting energy are determined.
•Presents a statistical approach for investigation of progressive tool wear.•The effect of cutting parameters on tool wear were analyzed with ANOVA.•AE sensor and dynamometer were evaluated for ...detection of tool breakage.•Taguchi based prediction was compared with experimental results.•Optimization of machining parameters during turning were obtained.
On-line monitoring of tool wear and tool breakage are very important to reduce production costs through the optimization of machining parameters. Increasing cutting forces affect workpiece quality and tool condition that is the ultimate aim of production line and progressive tool wear which can trigger the tool breakage. Taguchi method is extensively used for determining number of experiment while variance analysis (ANOVA) deals with which parameter/s is/are effective on output. This study contains experiments and optimization processes during turning of AISI 1050 material with 3 input parameters (cutting speed, feed rate, tool tip) using Taguchi method. In order to determine the condition of the cutting tool, measurement of tangential cutting force and acoustic emission (AE) were carried out during metal removing. ANOVA results showed that cutting speed is the most effective about %45 and tool tip is the second about %35 on tool wear. On the other hand, the effect of feed rate on tangential cutting force (%88) and cutting speed on AE (%80) is remarkably higher than the other two parameters. In order to obtain the minimum tool wear value, the optimum cutting parameters have been selected as v1 = 135 m/min, f2 = 0,214 mm/rev, T2 = P25. By implemented sensor system tool breakage can be successfully detected and used for producing high quality materials with low costs.
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