Determination of temperature distribution in the cutting zone using hybrid analytical-FEM technique
Abstract In this study, the temperature distribution in the cutting zone was determined by integrating thermal analytical and simulation models of orthogonal cutting process with uncoated and coated carbide tools. Primarily, 2D FEM simulations were run to provide numerical solutions of temperatures occurring at different points through the chip/tool contact region and the coating/substrate boundary under defined cutting conditions. In addition, an analytical model for heat transfer in the cutting tool and its partitioning, proposed in References [W. Grzesik, P. Nieslony, Physics based modelling of interface temperatures in machining with multilayer coated tools at moderate cutting speeds, I…
Wavelet and fractal approach to surface roughness characterization after finish turning of different workpiece materials
In this paper, the surface profiles generated in longitudinal turning operations were characterized using continuous wavelet transform (CWT) and normalized fractal dimension Dn. In the comparative analysis, some characteristic roughness profiles after the turning of different workpiece materials, such as C45 medium carbon steel, nodular cast iron and hardened (55 HRC) high-strength alloy steel were selected. For wavelet characterization, both Morlet and ‘Mexican hat’ analyzing wavelets, which allow the assessment of extrema and frequency distribution, were utilized. The results of the CWT as a function of profile and momentary wavelet length are presented. It is concluded that CWT can be us…
Trends in Metal Cutting Theory and Practice
This chapter provides the state-of-the-art manufacturing systems that utilize various machining technologies in different manufacturing sectors. It highlights the challenges of the 21st-century manufacturing environment and characterizes numerous driven factors in modern machining technologies. They include more-established technologies, such as High-Speed Machining/Cutting, High-Performance Machining/Cutting, High-Efficiency Machining or currently developed ones, such as resource- and energy-efficient (generally sustainable) and hybrid machining. Practical examples and charts that document their importance in modern manufacturing are provided. Finally, some important future trends are over…
Friction behaviour of heat isolating coatings in machining: mechanical, thermal and energy-based considerations
Abstract This paper deals with possible modifications of the frictional behaviour exhibited during the cutting process resulting from the influence of the most-commonly used heat isolating coatings deposited on a WC-Co carbide substrate. For this study, three- and four-layered coatings with intermediate Al 2 O 3 ceramic layer and a monolayer TiAlN coating, which offer superior thermal protection of the carbide substrate, were examined. Orthogonal cutting tests were carried out by end-turning medium carbon steel and austenitic stainless steel workpieces. The experimental study was aimed at determining the fundamental frictional characteristics: dimensions of the tool-chip contact area, the f…
The role of coatings in controlling the cutting process when turning with coated indexable inserts
Abstract This paper is concerned with the variations in the specific cutting pressure and the tool–chip interface temperature that occur when machining a medium carbon steel and an austenitic stainless steel with TiC-, TiC/TiN- and TiC/Al2O3/TiN- coated inserts. Extensive experimental studies involving the cutting force and the interface temperature were performed. A standard thermocouple embedded in the workpiece was used to determine the cutting temperature. Two new parameters were introduced in order to compare both the mechanical and thermal loadings of the tool–chip contact for coated flat-faced and grooved inserts. Some optimal coating structures for high speed machining of these stee…
The influence of thin hard coatings on frictional behaviour in the orthogonal cutting process
New knowledge about the tribological response deriving from the interaction of the substrate/coating-chip system, with special attention to the orthogonal cutting process when chatter-free end turning using natural contact tools, is developed. In order to evaluate the frictional behaviour of this process under modified contact conditions, experimental investigations including the contact temperature, the contact loads, friction and the frictional heat flux per unit area were carried out. In contrast to the most obvious approach, the coefficient of sliding friction versus the cutting speed, the contact temperature, the normal pressure and the interface control factor is considered. A number …
Experimental investigation of the influence of adhesion on the frictional conditions in the cutting process
Abstract This paper presents the results of an experimental study on the influence of adhesion on the tribological characteristics of the tool-chip interface. It was established that under orthogonal cutting conditions both the high interface temperature and severe plastic deformation result in relatively strong adhesion between steel and uncoated carbide. In particular, the molecular–mechanical theory of friction was applied to estimate the shear strength of the local adhesive junction, and to divided the rake face friction into two terms—an adhesion term (the interfacial coefficient of friction) and the deformation term. It should be pointed out that the data obtained provide a new approa…
Tool Wear and Damage
This chapter provides comprehensive knowledge regarding tool wear mechanisms and characterizes their physical fundamentals. Adhesion, abrasion, diffusion and oxidation are selected as predominant mechanisms controlling tool wear, depending on the mechanical and thermal conditions at the rake and flank faces. The analytical models describing the wear rate and volumetric material loss for different wear mechanisms are provided. The tool wear indicators related to crater, flank and notch wear specified in ISO 3685 are presented for both flat-faced and grooved tools. Tool life is defined and corresponding models, including the influence of cutting speed, feed and the depth of cut, are derived. …
Friction and wear testing of multilayer coatings on carbide substrates for dry machining applications
Abstract The principle aim of this paper is to investigate three wear-protective coatings with multilayer structures, which are frequently used in the cutting tool industry and to assess their frictional behaviour under the test conditions equivalent to those for the cutting of medium carbon steel. A modified pin-on-disc tester was used to conduct experiments in which both the friction coefficient and the linear wear of the tribo-pair were recorded vs. sliding distance. The volumetric wear rate was proposed as a parameter for quantitative comparison of the wear resistance of the tribo-pairs tested. It was found that the principle stage of the specimen wear takes place during the first 200–2…
Frictional behaviour of oxygen diffusion hardened titanium in dry sliding against Co–28Cr–5W–4Fe–3Ni–1Si cobalt alloy
Abstract The results of conformal pin-on-disc tribological tests of a hard layer of the solid solution of oxygen in α-titanium sliding against a Co–28Cr–5W–4Fe–3Ni–1Si cobalt alloy counterspecimen are presented. The α-Ti(O) layer was diffusely produced over 2–8 h of oxidising in the superficial zone of a technical quality titanium specimen. The friction and wear responses of the system were recorded and the wear mechanisms were studied. Investigations of the material structure and chemical constitution in micro-areas of the titanium specimen, cobalt alloy counterspecimen and wear debris formed in dry sliding were performed with a Philips XL20 microscope equipped with an EDAX analyser. Crush…
Physics based modelling of interface temperatures in machining with multilayer coated tools at moderate cutting speeds
Abstract A new thermal model is presented for turning with tools with multilayer coatings. In the previous paper [Int. J. Mach. Tools Manuf. 43 (2003) 1311] devoted to the thermal problems in dry turning of steels with tools treated with multilayer coatings with an intermediate Al 2 O 3 layer new analytical models for estimating the heat partition to the chip and the average interface temperature were derived and the predictions were compared with experimental results. In this paper, a physics based modelling concept has been applied to both the individual layer and the composite layer approach to develop an estimate of the average and the maximum steady-state chip-tool interface temperatur…
Surface Integrity
This chapter provides comprehensive knowledge regarding the state and properties of both surface and subsurface layers generated during machining processes, including different associated mechanical and thermal influences. Basic models of the superficial layer and factors effecting surface integrity are presented. Decomposition of surface topography into roughness, waviness and form along with appropriate filtering methods is outlined. The characterization of surface roughness based on 2D and 3D roughness parameters as well as motif, fractal and frequency characteristics are presented. In particular, all standardized areal surface parameters are specified, and practical examples are provide…
Cutting Vibrations
Chapter 8 provides comprehensive engineering knowledge regarding cutting vibrations, their typical sources in machining operations, and methods of their elimination to prevent negative influence on the surface finish (chatter marks). The classification of cutting vibrations including free, forced, and self-excited vibrations is discussed, and all possible sources and mechanisms of all types of cutting vibrations are specified and characterized. The regeneration of surface waviness, which is the predominant mechanism of chatter, is outlined for turning and milling operations. The stability of machining operations based on the stability lobe diagrams is highlighted and their practical applica…
The mechanics of continuous chip formation in oblique cutting with single-edged tool—part II. Experimental verification of the theory
Abstract Experimental results obtained during oblique cutting of annealed steel Ck 45 (SAE-AISI 1045) with a single-edged tool are presented. Extensive measurements of forces, cutting ratio, chip flow angle etc. have been carried out under a wide range of cutting conditions. The measured data obtained from these cutting tests are used to test assumptions proposed in the first part of this work. In relation to previous works dealing with oblique cutting problems the present one extends to tools with angles of tool obliquity ranging from 30° to 70° and having a large negative rake angle.
Experimental investigation of the cutting temperature when turning with coated indexable inserts
Abstract This paper deals with an experimental investigation into the different factors which influence the temperature which occur at the coating/substrate–chip interface when machining a medium carbon steel and an austenitic stainless steel. Both flat-faced and grooved inserts coated with TiC, TiC/TiN and TiC/Al 2 O 3 /TiN were used. A standard K-type thermocouple embedded in the workpiece was used to convert measured efms to the interfacial temperature. Some optimal coating structures for high speed machining of these steels corresponding to the minimum interface temperature were selected. In particular, it was observed that by the proper selection of the thermal properties of the coatin…
The mechanics of continuous chip formation in oblique cutting with single-edged tool — Part I. Theory
Abstract The paper presents a new point of view on oblique cutting mechanics when cutting with a single-edged tool. This is based on the main assumption that plastic flow of material during chip forming occurs in the set of planes normal to the cutting edge. As a consequence of the transformation of various orthocartesian systems some new generalized relationships for kinematics of oblique cutting operation and plastic deformation in the shear zone are derived.
Finite difference analysis of the thermal behaviour of coated tools in orthogonal cutting of steels
Abstract Temperature measurement and prediction have been a major focus of machining for several decades but now this problem became more important due to the wider use of advanced cutting tool coatings. Practically, there is a lack of simulation programs for prediction of the temperatures in the cutting zone when machining with differently coated cutting tools. In all literature items cited the finite difference methods (finite difference approaches) were used to find the distribution of temperature inside the uncoated tool body or along the tool–chip interface for continuous (turning) and interrupted (milling) machining processes. The algorithm applied overcomes this limit. In this study,…
Hybrid approach to surface roughness evaluation in multistage machining processes
Abstract An assessment of surface quality in turned, ground and honed specimens is made by means of a computer-based processing of digitised surface profiles. Three different methods of surface finish characterisation, i.e. statistical, fractal and neural network-based approaches are examined and compared. Correlations between some representative roughness parameters and the fractal dimension (D) values estimated were found. Consequently, they can be converted to their corresponding roughness parameters, i.e. Ra, Rz and RΔa. Finally, a set of parameters including the minimum surface finish data for machining of external cylindrical surfaces when using complex technological process, is propo…
An Investigation of the Cutting Process for Chip Breaking Monitoring in Turning of Steels
This paper presents some results of an experimental study on chip breaking monitoring when turning steels with chip forming inserts. In the first part of this study the recognition of chip forms by means of cutting force analysis in the frequency domain is described. Generally, the present work is concerned with the use of the interface control factor for determining the transition from unacceptable chip forms to the chip breaking. For this purpose experiments under approximately orthogonal machining conditions including measuring the shear strain, the cutting energy and the average interface temperature are carried out. The obtained results confirmed that the initiation of acceptable chip …
Advanced Machining Processes
This chapter provides comprehensive knowledge regarding both well-established achievements in manufacturing and new trends in improving machining processes, taking into account physical, design and technological aspects. The background of machining advancements is outlined, including all components of the machining system and typical machining operations such as turning, milling and drilling and different construction materials. In particular, this short survey covers such machining techniques as high-speed machining/cutting (HSM/HSC), hard part machining, dry and near-dry machining (MQL), high-performance machining (HPM), multitasking/complete machining, and assisted and hybrid machining. …
An integrated approach to evaluating the tribo-contact for coated cutting inserts
Abstract The orthogonal machining process when end turning medium carbon and austenitic stainless steels with cemented WC-Co tools coated with single-layer (TiC), two-layer (TiC/TiN), and three-layer (TiC/Al2O3/TiN) hard thin films was investigated. Extensive experimental investigations including the thermal, mechanical and tribological responses of the tribo-contact between the coating–substrate system and the chip, under different cutting conditions, were carried out. The study sheds light on the cutting forces, the interface temperatures and the tribo-contact conditions, including the friction energy dissipated at the tool–chip interface, the frictional heat flux conducting into either t…
Modelling and Simulation of Machining Processes and Operations
This chapter provides the state-of-the-art knowledge engineering and modelling techniques applied in manufacturing/machining and overviews future trends observed at a global scale. Modelling methods for machining processes and operations are classified. The chapter also highlights the multiple tasks of modelling and simulation in modern machining/manufacturing systems. The most popular techniques of numerical simulation including finite difference method and finite element method (FEM) related to mechanical and thermal problems arising in machining processes are described. Practical examples of FE models of various metal cutting operations and their importance in modern manufacturing are pr…
Prediction of friction and heat flow in machining incorporating thermophysical properties of the coating–chip interface
Abstract This paper deals with an experimental and analytical investigation into the thermodynamically activated effects influencing the behaviour of the multi-layered coated tool rake face during orthogonal cutting of ferromagnetic and paramagnetic steels. Temperature measurements on the tool rake face using a thermocouple-based technique and identification of the contact zone by means of computer image processing were carried out. New methodology for assessing friction and the amount of thermal energy generated when machining with a coated tool insert with natural and restricted contact coupled with a metallic chip, using thermophysical properties of the sliding materials is developed in …
Machining Economics and Optimization
This chapter provides comprehensive knowledge regarding economical considerations and possible optimization methods of machining operations. The background of machining economics, including costs, time and productivity, related for typical machining operations (such as turning, milling and drilling) is outlined. The components of machining costs and time related to the cutting speed are distinguished, and appropriate mathematical models are presented. Optimization procedures allowing selection of optimal values of cutting speed and feed rate based on tool life and energy efficiency criteria are overviewed. In the first case, the economic cutting speed and cutting speed corresponding to the …
FINITE DIFFERENCE METHOD-BASED SIMULATION OF TEMPERATURE FIELDS FOR APPLICATION TO ORTHOGONAL CUTTING WITH COATED TOOLS
ABSTRACT A finite difference method was proposed to model the effect of a variety of tool coatings on the magnitude and distribution of temperatures through the tool-chip contact region and the coating/substrate boundaries. For each workpiece-tool pair tested the intensity of uniformly distributed heat flux and relevant analytically obtained values of the heat partition coefficient were assumed to change with variations of cutting speed and the corresponding friction. In this case the simulation of an orthogonal machining of AISI 1045 steel was performed using special computing algorithm with elementary balances of induced energies (MBE). It is concluded that the temperature contours obtain…
An Investigation of the Thermal Effects in Orthogonal Cutting Associated with Multilayer Coatings
Abstract This paper deals with an experimental and analytical investigation into the tool-chip interface behaviour, influencing the temperature and heat transfer at the multilayered coated-tool rake face during orthogonal cutting of carbon and stainless steels. New methodology for assessing the amount of thermal energy generated when machining with a coated tool insert with natural and restricted contact coupled with a metallic chip, using thermophysical properties of the sliding materials is developed in this study. It was proven, based on the heat flux analysis, that the use of advanced coatings with an intermediate Al 2 O 3 layer can substantially improve the heat flow into the chip at d…
Nanomanufacturing/Nanotechnology
This chapter provides comprehensive knowledge regarding the fabrication of nanoproducts and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques, such as nanomachining (ultra-precision) and new trends in improving nanoprocesses taking into account AFM, laser beam machining, electron beam machining processes are overviewed. The background of nanomachining processes, including typical machining operations such as turning, milling and grinding and different construction materials (metallic and nonmetallic), is outlined. The physical mechanisms responsible for the transition from brittle to ductile regime machining are explained. Mo…
Influence of machining conditions on friction in metal cutting process – A review
This paper presents a range of variable machining factors which influence substantially friction directly or by the tool wear developed in the cutting zone. The group of direct factors include the workpiece and cutting tool materials coupled, the cutting/sliding velocity, cooling media supplied to the tool-chip contact zone, modification of the tool contact faces by micro-texturing. Special attention was paid to the tool wear evolution and its pronounced effect on changes of the contact conditions.
Cutting Tool Materials
This chapter provides the state-of-the-art materials engineering sector that produces cutting tool materials for different manufacturing branches. It highlights the special demands on this special material group for modern machining technologies. Five groups of cutting tool materials are characterized in terms of their mechanical and thermo-physical properties: high-speed steels, sintered tungsten carbides, cermets, ceramics and superhard materials, all as conventional (uncoated) and coated grades. The most popular techniques of coating deposition on various substrates are described. Practical examples of cutting tool inserts made of various materials produced by leading world manufacturers…
Analytical Models Based on Composite Layer for Computation of Tool-Chip Interface Temperatures in Machining Steels with Multilayer Coated Cutting Tools
In this study the method of elementary balances (MBE) is applied to predict the temperature fields in uncoated and coated carbide cutting tools. Numerical computations are supported by the experimentally/analytically obtained values of the contact length, the total heat flux and the heat partitioning. The changes in the tool temperature maps, resulting from variable thermal properties of tested materials are considered. In particular, the distribution of temperature across the thin film of 0.01 mm and corresponding temperature rise distribution curves along the rake and flank faces are completely displayed. The simulations have been validated against the measured average rake face temperatu…
Virtual/Digital and Internet-based Machining
This chapter provides comprehensive knowledge regarding the application of various virtual digital and information techniques to machining processes and machine tools, and their simulation and visualization. A number of manufacturing concepts used in modern industry, such as Internet-based manufacturing, digital manufacturing, virtual manufacturing and telemanufacturing, are characterized. In particular, architectures of digital manufacturing and virtual manufacturing, along with their practical applications, are presented. The architecture of the virtual machine tool and numerous examples of simulations of machining process performing on multi-axis/multitasking are visualized. Moreover, vi…
Cutting Fluids
This chapter provides comprehensive knowledge regarding cutting fluids (CFs), their classifications and basic categories, including non-water-miscible, water-miscible and water-based CFs. Main properties and application areas of these three CFs are characterized and specified. Such effects as cooling, lubricating and processing (i.e., the influence on the behaviour of the cutting process) resulting from supplying CFs are outlined. The strategies of delivering CFs to the cutting zone, including flooding, external and internal supply of pressured CFs, along with minimum-quantity lubrication techniques as well as cryogenically cooled gases (CO2 snow and liquid nitrogen (LN2)) are described. So…
Heat in Metal Cutting
This chapter provides comprehensive knowledge regarding thermal effects during the cutting process with both uncoated and coated cutting tools. Main heat sources and flowing heat fluxes into the tool, chip and workpiece are characterized and quantified. The heat distribution models that allow the analytical prediction of heat partition between the tool and the chip are specified. They consider such thermal properties as specific heat, thermal conductivity and diffusivity, Peclet thermal number, and heat transmission ratio, all as functions of temperature. Finite element method and finite difference method simulations applied to the prediction of temperature fields are outlined for turning a…
Finite element modelling of temperature distribution in the cutting zone in turning processes with differently coated tools
Abstract The aim of this study is to check the applicability of various simulation models to obtain finite element solutions of cutting forces, specific cutting energy and adequate temperatures for a range of coated tool materials and defined cutting conditions. Commercial explicit finite element code Thirdwave AdvantEdge has been used in simulations of orthogonal cutting processes performed by means of uncoated carbide and coated tools. The latter were equipped with progressively increasing number of thin layers including TiC, TiN and Al 2 O 3 films deposited onto ISO P20 carbide substrates. Results showing the tool–chip interfacial friction influencing the temperature distribution fields,…
Micro-machining
This chapter provides comprehensive knowledge regarding the fabrication of micro-products and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques such as micro-machining and new trends in improving micro-processes taking into account EDM, laser, FIB, LIGA and DRIE processes are overviewed. The background of micro-machining processes, including typical machining operations such as turning, milling and drilling and different construction materials, is outlined. Moreover, a special focus was made on new constructions, control systems and effective applications of micro-machining techniques. In addition, the focus was directed towa…
Comparative assessment of surface roughness produced by hard machining with mixed ceramic tools including 2D and 3D analysis
Abstract This paper provides a new comprehensive analysis of part surface finish in continuous dry turning of a hardened construction steel when using mixed alumina cutting tools. Consequently, the surface profiles (2D arragement) and surface microstereometries (3D arragement) generated during different hard part turning operations on a 40H low chromium alloy steel (equivalent to AISI 5140 or DIN 41Cr4), heat treated to the hardness of about 60 HRC, were evaluated. As a result, this paper aggregates the multi-parameters characterization of the surface roughness with the machined surface structure obtained at the three selected feed rates and constant cutting speed of 100 m/min. Results show…
A computational approach to evaluate temperature and heat partition in machining with multilayer coated tools
Abstract In this paper, analytical models for estimating the interface temperature and heat partition to the chip in continuous dry machining of steels with flat-faced tools treated with multilayer coatings are presented. The database for modeling includes changes in the thermal properties of both workpiece and substrate/coating materials and the Peclet and Fourier numbers occurring at actual interface temperatures. Process outputs involve the average tool–chip interface temperature, the tool–chip contact length, the friction energy and the heat balance between the moving chip and stationary tool. It was found that the heat partition coefficient varies significantly from 0.65 to 0.8 when us…
Investigations on friction and wear mechanisms of the PVD-TiAlN coated carbide in dry sliding against steels and cast iron
Abstract The tribological behaviour of the monolayer PVD-titanium aluminium nitride (TiAlN) coated carbide inserts in unidirectional dry sliding against steel and cast iron counterparts was investigated using the pin-on-disc standard test with varying sliding speeds and normal loads. Three different materials of various machinability rates were used as the counterparts, namely the normalised medium carbon steel C45 equivalent to AISI 1045, austenitic stainless steel 1H18N9T equivalent to AISI 304 and gray cast iron EN-GJL-300 with flake-shaped graphite. A pin-on-disc device with round tool inserts was used to conduct friction and wear tests in which both the friction coefficient and the lin…
Micro-Machining
This chapter provides comprehensive knowledge regarding the fabrication of micro-products and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques such as micro-machining and new trends in improving micro-processes taking into account EDM, laser, FIB, LIGA and DRIE processes are overviewed. The background of micro-machining processes, including typical machining operations such as turning, milling and drilling and different construction materials, is outlined. Moreover, a special focus was made on new constructions, control systems and effective applications of micro-machining techniques. In addition, the focus was directed towa…
Machinability of Engineering Materials
Chapter 13 provides comprehensive knowledge regarding machinability of construction materials and characterizes various meanings of this specific material feature, allowing effective selection of machining conditions. Factors affecting machinability and typical causes of low machinability are discussed. Three groups of machinability criteria are selected, including basic, substitutive and auxiliary ones. In particular, the cutting speed corresponding to economic or high productivity criteria and obtainable surface roughness are distinguished as basic machinability criteria. Relative and absolute machining rating systems are highlighted, and appropriate material groups and values of the mach…
Nanomanufacturing/Nanotechnology
This chapter provides comprehensive knowledge regarding the fabrication of nanoproducts and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques, such as nanomachining (ultra-precision) and new trends in improving nanoprocesses taking into account AFM, laser beam machining, electron beam machining processes are overviewed. The background of nanomachining processes, including typical machining operations such as turning, milling and grinding and different construction materials (metallic and nonmetallic), is outlined. The physical mechanisms responsible for the transition from brittle to ductile regime machining are explained. Mo…
Orthogonal and Oblique Cutting Mechanics
This chapter provides the engineering knowledge and modelling techniques applied in description of the material behaviour in the cutting zone resulting in chip formation and its separation from the bulk material. Geometrical and kinematical characteristics of orthogonal and oblique cutting models are classified and specified. Forces acting on the cutting tools and their measurement methods for several machining operations, such as turning, milling, drilling, boring and grooving, are presented. Moreover, forces acting in the cutting zone and their resolution on the shear plane and the rake and flank faces, along with stress distributions, are presented. The chapter highlights how components …
Thermophysical-Property-Based Selection of Tool Protective Coatings for Dry Machining of Steels
A method is proposed for determining the optimum cutting conditions in dry turning of carbon and stainless steels using multilayer coated tools for physical criteria such as the maximum temperature of a cutting tool or maximum heat flux. The modified thermal number describing the tool-chip behavior, is introduced. The correlation between the thermal number and the average tool-chip interface temperature and frictional heat flux is examined for both flat-faced and grooved rake configurations. Although not shown here directly, the thermal barrier effect observed for multilayer coatings with an intermediate Al2O3 layer increases the heat partition to the chip at substantially reduced cutting t…
Surface finish generated in hard turning of quenched alloy steel parts using conventional and wiper ceramic inserts
Abstract Significant progress has already been achieved in green manufacturing including dry and hard, often high-speed, machining technologies. For instance, the demand for higher productivity has resulted in the wider application of ceramic and PCBN tools with special multi-radii (wiper) geometry. This paper reports some important characteristics of the surface roughness produced in the turning of a hardened low-chromium alloy steel using mixed alumina–titanium carbon (TiC) ceramic cutting tools equipped with both conventional and wiper inserts. The characteristic geometrical features of surfaces obtained in both these turning operations have been assessed by means of representative two-d…
Composite layer-based analytical models for tool–chip interface temperatures in machining medium carbon steels with multi-layer coated cutting tools
Abstract This investigation is devoted to the thermal problems in dry orthogonal turning of a C45 medium carbon steel with natural contact tools treated with multi-layer coatings with an intermediate Al 2 O 3 layer. New hybrid analytical models for estimating heat partition to the chip and the tool–chip interface temperatures were proposed. Furthermore, the physics-based modelling concept, which applies composite layer approach was developed to estimate the average and maximum steady-state tool–chip interface temperatures in orthogonal turning. The model predictions were compared to appropriate experimental process data using natural tool-work thermocouples and other simulated and measured …
Metal Cutting Operations and Terminology
This chapter presents a general description of the machining processes and machining operations using various classification criteria. The classification of machining processes is based on the energy source used and the type of generating mechanisms, whereas the classification of machining operations utilizes characteristic motions describing their kinematics. Some examples of turning, milling, hole making, broaching and threading operations are provided. Kinematics of typical cutting operations and appropriate standardized cutting parameters are described. The geometry of cutting tools in the tool-in-hand and tool-in-use systems, including relevant tool angles, is characterized.
Tribology of Metal Cutting
This chapter provides comprehensive knowledge regarding tribological behaviour of the cutting zone and characterizes specific features of the tool–chip contact that influence friction mechanisms in this area. Adhesion, plastic deformation of contacting asperities and ploughing action of the cutting edge are selected as three predominant mechanisms controlling sliding friction between the tool and the chip. The two-zone model of the tool–chip contact distinguishing seizure and sliding regions is characterized, along with experimental evidence based on photoelastic and material flow line techniques. Corresponding stress distributions for plane and restricted-contact cutting tools are provided…
Chip Formation and Control
This chapter provides comprehensive engineering knowledge and modelling techniques applied in description of chip formation in the cutting zone and its separation from the bulk material, flow, and final breaking. Possible classification systems, including different chip shapes and physical mechanisms of their formation, are specified. The mechanisms of brittle fracture-based and shear-type chips are characterized in terms of plastic deformation and fracture mechanics. The models of the shear angle using different mechanical approaches are discussed. In addition, representative examples of FEM simulations of different types of chips for turning and milling operations are presented. Formulas …
Sensor-Assisted Machining
This chapter provides comprehensive knowledge regarding the application of various sensors and monitoring techniques to machining processes, cutting tools and machine tools. A number of monitoring methods used in manufacturing and relevant sensors are characterized. In particular, three most frequently used sensors, i.e., force, acceleration and acoustic emission, are presented and their characteristics and advantages are highlighted. The architectures of multiple-sensor tool-monitoring systems for detection of tool wear and breakage and collision for machine tools, including details of sensor fusion, signal processing and decision-making, are presented. Moreover, the concepts of sensor-bas…