Prediction of Wearing of Cutting Tools Using Real Time Machining Parameters and Temperature Using Rayleigh-Ham Method

Wear of cutting tools is a big concern for industrial manufacturers, because of their acquisition cost as well as the impact on the production lines when they are unavailable. Law of wear is very important in determining cutting tools lifespan, but most of the existing models don’t take into account the cutting temperature. In this work, the theoretical and experimental results of a dynamic study of metal machining against cutting temperature of a treated steel of grade S235JR with a high-speed steel tool are provided. This study is based on the analysis of two complementary approaches, an experimental approach with the measurement of the temperature and on the other hand, an approach using modeling. Based on unifactorial and multifactorial tests (speed of cut, feed, and depth of cut), this study allowed the highlighting of the influence of the cutting temperature on the machining time. To achieve this objective, two specific approaches have been selected. The first was to measure the temperature of the cutting tool and the second was to determine the wear law using Rayleigh-Ham dimensional analysis method. This study permitted the determination of a law that integrates the cutting temperature in the calculations of the lifespan of the tools during machining.

INFLUENCE OF COLD NITROGEN GAS AND OIL MIST IN MACHINING NICKEL-BASE K424 ALLOY WITH CERAMIC CUTTING TOOLS

The role of cold nitrogen gas and oil mist on tool wear and surface roughness is investigated in turning the K424 nickel-base super alloy with Sialon and SiC whisker-reinforced alumina ceramic tools. A new cooling system is developed and used to lower the temperature of the compressed nitrogen gas. Experiments are performed in three different cooling/lubrication modes, i.e. the dry cutting, the cold nitrogen gas （CNG）, and the cold nitrogen gas and oil mist （CNGOM）. Experimental results show that the depth-of-cut notching severely limits the tool life in all the cooling/lubrication modes. Compared with the dry cutting, the use of CNG and CNGOMcan yield higher wear rate of depth-of-cut notching and worse surface finish.

Smart Cutting Tools and Smart Machining: Development Approaches, and Their Implementation and Application Perspectives

Smart machining has tremendous potential and is becoming one of new generation high value precision manufacturing technologies in line with the advance of Industry 4.0 concepts. This paper presents some innovative design concepts and, in particular, the development of four types of smart cutting tools, including a force-based smart cutting tool, a temperature-based internally-cooled cutting tool, a fast tool servo （FTS） and smart collets for ultra- precision and micro manufacturing purposes. Implemen- tation and application perspectives of these smart cutting tools are explored and discussed particularly for smart machining against a number of industrial application requirements. They are contamination-free machining, machining of tool-wear-prone Si-based infra-red devices and medical applications, high speed micro milling and micro drilling, etc. Furthermore, implementation tech- niques are presented focusing on： （a） plug-and-produce design principle and the associated smart control algo- rithms, （b） piezoelectric film and surface acoustic wave transducers to measure cutting forces in process, （c） critical cutting temperature control in real-time machining, （d） in- process calibration through machining trials, （e） FE-based design and analysis of smart cutting tools, and （f） applica- tion exemplars on adaptive smart machining.

Dynamic Reliability Sensitivity of Cemented Carbide Cutting Tool

Influence of geometric and cutting parameters of cemented carbide cutting tool on reliability of cutting tool has become more and more mature, yet influence of its physical and material parameters on reliability is still blank. In view of this, cutting test and fatigue crack growth test of YT05 cemented carbide cutting tool are conducted to measure such data as the original crack size, growth size, times of impact loading, number and time of cutting tool in failure, and stress distribution of cutting tool is also obtained by simulating cutting process of tools. Mathematical models on dynamic reliability and dynamic reliability sensitivity of cutting tool are derived respectively by taking machining time and times of impact loading into account, thus change rules of dynamic reliability sensitivity to physical and material parameters can be obtained. Theoretical and experimental results show that sensitive degree on each parameter of tools increases gradually with the increase of machining time and times of impact loading, especially for parameters such as fracture toughness, shape parameter, and cutting stress. This proposed model solves such problems as how to determine the most sensitive parameter and influence degree of physical parameters and material parameters to reliability, which is sensitivity, and can provide theoretical foundation for improving reliability of cutting tool system.

Synergistically Toughening Effect of SiC Whiskers and Nanoparticles in Al_2O_3-based Composite Ceramic Cutting Tool Material

In recent decades, many additives with different characteristics have been applied to strengthen and toughen Al2O3-based ceramic cutting tool materials. Among them, SiC whiskers and SiC nanoparticles showed excellent performance in improving the material properties. While no attempts have been made to add SiC whiskers and SiC nanoparticles together into the ceramic matrix and the synergistically toughening effects of them have not been studied. An Al2O3-SiCw-SiC np advanced ceramic cutting tool material is fabricated by adding both one-dimensional SiC whiskers and zero-dimensional SiC nanoparticles into the Al2O3 matrix with an effective dispersing and mixing process. The composites with 25 vol% SiC whiskers and 25 vol% SiC nanoparticles alone are also investegated for comparison purposes. Results show that the Al2O3-SiCw-SiCnp composite with both 20 vo1% SiC whiskers and 5 vol% SiC nanoparticles additives have much improved mechanical properties. The flexural strength of Al2O3-SiCw-SiCnp is 730＋ 95 MPa and fracture toughness is 5.6 ± 0.6 MPa.m1/2. The toughening and strengthening mechanisms of SiC whiskers and nanoparticles are studied when they are added either individually or in combination. It is indicated that when SiC whiskers and nanoparticles are added together, the grains are further refined and homogenized, so that the microstructure and fracture mode ratio is modified. The SiC nanoparticles are found helpful to enhance the toughening effects of the SiC whiskers. The proposed research helps to enrich the types of ceramic cutting tool and is benefit to expand the application range of ceramic cutting tool.

Approach for Polishing Diamond Coated Complicated Cutting Tool: Abrasive Flow Machining(AFM)

Lower surface roughness and sharper cutting edge are beneficial for improving the machining quality of the cut?ting tool, while coatings often deteriorate them. Focusing on the diamond coated WC?Co milling cutter, the abrasive flow machining(AFM) is selected for reducing the surface roughness and sharpening the cutting edge. Comparative cutting tests are conducted on di erent types of coated cutters before and after AFM, as well as uncoated WC?Co one, demonstrating that the boron?doped microcrystalline and undoped fine?grained composite diamond coated cutter after the AFM(AFM?BDM?UFGCD) is a good choice for the finish milling of the 6063 Al alloy in the present case, because it shows favorable machining quality close to the uncoated one, but much prolonged tool lifetime. Besides, compared with the micro?sized diamond films, it is much more convenient and e cient to finish the BDM?UFGCD coated cutter covered by nano?sized diamond grains, and resharpen its cutting edge by the AFM, owing to the lower initial surface roughness and hardness. Moreover, the boron incorporation and micro?sized grains in the underly?ing layer can enhance the film?substrate adhesion, avoid the rapid film removal in the machining process, and thus maximize the tool life(1040 m, four times more than the uncoated one). In general, the AFM is firstly proposed and discussed for post?processing the diamond coated complicated cutting tools, which is proved to be feasible for improving the cutting performance

Advances in micro cutting tool design and fabrication

Microcutting is a precision technology that offers flexible fabrication of microfeatures or complex three-dimensional components with high machining accuracy and superior surface quality.This technology may offer great potential as well as advantageous process capabilities for the machining of hard-to-cut materials,such as tungsten carbide.The geometrical design and dimension of the tool cutting edge is a key factor that determines the size and form accuracy possible in the machined workpiece.Currently,the majority of commercial microtools are scaled-down versions of conventional macrotool designs.This approach does not impart optimal performance due to size effects and associated phenomena.Consequently,in-depth analysis and implementation of microcutting mechanics and fundamentals are required to enable successful industrial adaptation in microtool design and fabrication methods.This paper serves as a review of recent microtool designs,materials,and fabrication methods.Analysis of tool performance is discussed,and new approaches and techniques are examined.Of particular focus is tool wear suppression in the machining of hard materials and associated process parameters,including internal cooling and surface patterning techniques.The review concludes with suggestions for an integrated design and fabrication process chain which can aid industrial microtool manufacture.

Wear Patterns and Mechanisms of Cutting Tools in High Speed Face Milling

High speed machining has received an important interest because it leads to an increase of productivity and a better workpiece surface quality. However, at high cutting speeds, the tool wear increases dramatically due to the high temperature at the tool-workpiece interface. Tool wear impairs the surface finish and hence the tool life is reduced. That is why an important objective of metal cutting research has been the assessment of tool wear patterns and mechanisms. In this paper, wear performances of PCBN tool, ceramic tool, coated carbide tool and fine-grained carbide tool in high speed face milling were presented when cutting cast iron, 45# tempered carbon steel and 45# hardened carbon steel. Tool wear patterns were examined through a tool-making microscope. The research results showed that tool wear types differed in various matching of materials between cutting tool and workpiece. The dominant wear patterns observed were rake face wear, flank wear, chipping, fracture and breakage. The main wear mechanisms were mechanical friction, adhesion, diffusion and chemical wear promoted by cutting forces and high cutting temperature. Hence, the important considerations of high speed cutting tool materials are high heat-resistance and wear-resistance, chemical stability as well as resistance to failure of coatings. The research results will be great benefit to the design and the selection of tool materials and control of tool wear in high-speed machining processes.

Parameter estimation of cutting tool temperature nonlinear model using PSO algorithm

In cutting tool temperature experiment, a large number of related data could be available. In order to define the relationship among the experiment data, the nonlinear regressive curve of cutting tool temperature must be constructed based on the data. This paper proposes the Particle Swarm Optimization (PSO) algorithm for estimating the parameters such a curve. The PSO algorithm is an evolutional method based on a very simple concept. Comparison of PSO results with those of GA and LS methods showed that the PSO algorithm is more effective for estimating the parameters of the above curve.

Influence of the Magnetic High-speed Steel Cutting Tool on Cutting Capability

The high-speed steel cutting tool has advantaged i n modern cutting tool for its preferable synthetical performance, especially, in a pplication of complicated cutting tools. Therefore, the study of the high-speed steel cutting tools that occupied half of cutting tools has become an importa nt way of studying on modern cutting technology. The cutting performance of hi gh speed-steel cutting tools will be improved by magnetization treating method. Microstructure of high-speed steel will be changed as a result of magnetizatio n, and the effect of mechanism and electromagnetism. Magnetic domain was re-arr anged under outer magnetic field for the magnetism of high-speed steel. When th e high-speed steel tools were treated in pulse magnetic field, the intensity H of which is get to 19 Kves, the boundary of magnetic domain will be replaced ham mered by this kind of intensive pulse, causing flexibility deformation and elast ic stress. The interaction between the elastic field and the initial dislo cation field will lead to expansion and transfer of dislocation, fining of g rains, distortion of crystal lattice, and increase of hardness. Obtained by expe riment, the hardness is raised HRC 0.6～0.9, it is to whole tool. Magnetized in p ulse magnetic field without measure, too many dislocations will accumulate on th e interface of, and the tool will be brittle. Many factors such as magnetic filed intensity, magnetization time and chemical c omponent of high-speed steel will influence the capability of magnetized cuttin g. This paper, according to the test, analyzed and compared the difference effec ts between the magnetized high-speed steel cutting tool and the non-magnet ized high-speed steel cutting tool on cutting force, power, heat, accuracy, ser vice life and etc. It also put forward the relation of cutting factor and cuttin g capability, and the relation of magnetic parameter and cutting capability.

Influence of Coolant on Cutting Tool Performance

This paper reports a Study carried out to substantiate or refute the belief that when coolant is applied, the cutting performance is actually improved. Experiments on cutting forces and chip geometry were conducted in which AISI 1050 Steel was machined by turning using P30 uncoated tungsten carbide tools. Experiments were performed on a CNC Okuma LH35-N lathe undermachining conditions commonly used in workshops in Singapore and many other parts of the world.

Comparing the Effectiveness of Coatings on Carbide andCermet Cutting Tool Inserts

A series of metal cutting experiments was performed on a CNC lathe to evaluate the performance of various coatings on different tool substrates. The workpiece material was plain medium carbon steel and the cutting tool materials were carbide and cermet inserts coated with various single as well as multilayer coatings. Machining was done under various cutting conditions of speed and feed-rate, and for various durations of Cutting. The output parameters studied were the cutting forces (axial, radial and tangential), the surface roughness of the workpiece, as well as the tool wear (crater and flank wear). From these results, the performances of the various cutting inserts are evaluated and compared. Results show that cutting forces are significantly lower when using coated cermets than when using coated carbides although different coatings on the same substrate also result in different cutting forces. However, there is less difference in the surface roughness of the finished workpiece for the various coatings and substrates.

The P40 Cutting Tool Wear Modelization Machining Fk20MnCr5

This work presents an experimental study to describe a wear zone in the P40 cutting tools used during a dry lathing. Mechanics of cutting has been presented to investigate the effects of edge geometry of the cutting tool carbide cutting insert. In the field of the metals cutting, the wear of the cutting tools leads to a degradation of the cutting zone and work. It is thus important to study the evolution of the cutting criteria allowing to follow the tool degradation during a manufacturing operations and thus to decide whether to replace the tool or not. Three parameters: cutting speed, cutting feed and cutting depth are considered to modelize the tool wear. An experimental device, particularly, a work-piece in Fk20MnCr5 material was cutted on a conventional lath for shaping, a high resolution sensor (HRS), had been used for measuring wear zone. The rela- tionship between “the cutting speed, the depth of cut, the feed rate” are analysed and modelled. In order to deduce this shape the spline method to modelize the wear zone has been used and a mathematical model has been proposed.

Precise measurement of geometric and physical quantities in cutting tools inspection and condition monitoring: A review

As one of the most important terminals in machining, cutting tools have been widely used for components manufacturing in aerospace and other industries. The quality of these components and processing efficiency are closely linked to the performance of cutting tools. Therefore, it is essential and critical to inspect the cutting tools and monitor the condition during the stage of manufacturing and machining. This review aims to discuss and summarize the key problems, methods,and techniques from the perspective of the tool geometric and the physical quantities measurement,including machine vision, physical sensors and data processing. It is worth mentioning that we focus on the topic of precision measurement methods and discuss universal solutions by identifying the common characteristics of the measured quantities. Eventually, the challenges and future trends for the development of in-depth research and practical applications are concluded. The research and application of precise measurement techniques for geometric and physical quantities will better promote the development of intelligent manufacturing.

Progress on Bionic Textured Cutting Tools:A Review and Prospects

Cutting tools are known as the“productivity”of the manufacturing industry,which affects the production efficiency and quality of the workpiece,and has become the focus of research and attention in academia and industry.However,traditional cutting tools often suffer from adhesion or wear during the cutting process,which considerably reduces the cutting efficiency and service life of the tools,and makes it difficult to meet current production requirements.To solve the above problems,scholars have introduced bionics into the tool’s design,applying the microscopic structure of the biological surface to the tool surface to alleviate the tool’s failure.This paper mainly summarizes the research progress of bionic textured cutting tools.Firstly,categorize whether the bionic texture design is inspired by a single organism or multiple organisms.Secondly,it is discussed that the non-smooth surface of the biological surface has five characteristics:hydrophilic lubricity,wear resistance,drag reduction and hydrophobicity,anti-adhesion,and arrangement,and the non-smooth structure of these different characteristics are applied to the surface of the tool is designed with bionic texture.Furtherly,the cutting performance of bionic textured cutting tools is discussed.The anti-friction and wear-resisting mechanism of bionic textured cutting tools is analyzed.Finally,some pending problems and perspectives have been proposed to provide new inspirations for the design of bionic textured cutting tools.

Magnetohydrodynamic‑based Internal Cooling System for a Ceramic Cutting Tool:Concept Design,Numerical Study,and Experimental Evalidation

The efective removal of the heat generated during mechanical cutting processes is crucial to enhancing tool life and produc-ing workpieces with superior surface fnish.The internal cooling systems used in cutting inserts employ a liquid water-based solvent as the primary medium to transport the excess thermal energy generated during the cutting process.The limitations of this approach are the low thermal conductivity of water and the need for a mechanical input to circulate the coolant around the inner chamber of the cutting tool.In this context,this paper proposes an alternative method in which liquid gallium is used as the coolant in combination with a magnetohydrodynamic(MHD)pump,which avoids the need for an external power source.Using computational fuid dynamics,we created a numerical model of an internal cooling system and then solved it under conditions in which a magnetic feld was applied to the liquid metal.This was followed by a simulation study performed to evaluate the efectiveness of liquid gallium over liquid water.The results of experiments conducted under non-cooling and liquid gallium cooling conditions were analyzed and compared in terms of the tool wear rate.The results showed that after six machining cycles at a cutting speed Vc=250 m min−1,the corner wear VBc rate was 75µm with the coolant of and 48µm with the MHD-based coolant on,representing a decrease of 36%in tool wear.At Vc=900 m min−1,the corner wear VBc rate was 75µm with the coolant of and 246µm with the MHD-based coolant on,representing a decrease of 31%in tool wear.When external cooling using liquid water was added,the results showed at Vc=250 m min−1,the diference between the tool wear rate reduction with the internal liquid gallium coolant relative to the external coolant was 29%.When the cutting speed was increased to Vc=900 m min−1,the diference observed between the internal liquid gallium coolant relative to the external coolant was 16%.The study proves the feasibility of using liquid gallium as a coolant to efectively remove thermal energy through internally fabricated cooling channels in cutting inserts.

Comparison of TiAlN, AlCrN, and AlCrN/TiAlN coatings for cutting-tool applications

Monolayer and bilayer coatings of TiAlN, AlCrN, and AlCrN/TiAlN were deposited onto tungsten carbide inserts using the plasma enhanced physical vapor deposition process. The microstructures of the coatings were characterized using scanning electron microscopy （SEM） and atomic force microscopy （AFM）. The SEM micrographs revealed that the AlrN and AlCrN/TiAlN coatings were uniform and highly dense and contained only a limited number of microvoids. The TiAIN coating was non-uniform and highly porous and contained more micro droplets. The hardness and scratch resistance of the specimens were measured using a nanoindentation tester and scratch tester, respectively. Different phases formed in the coatings were analyzed by X-ray diffraction （XRD）. The AlCrN/TiAlN coating exhibited a higher hardness （32.75 GPa）, a higher Young＇s modulus （561.97 GPa）, and superior scratch resistance （LcN = 46 N） compared to conventional coatings such as TiAlN, A1CrN, and TiN.

Cutting tool temperature prediction method using analytical model for end milling

Dramatic tool temperature variation in end milling can cause excessive tool wear and shorten its life, especially in machining of difficult-to-machine materials. In this study, a new analytical model-based method for the prediction of cutting tool temperature in end milling is presented.The cutting cycle is divided into temperature increase and decrease phases. For the temperature increase phase, a temperature prediction model considering real friction state between the chip and tool is proposed, and the heat flux and tool-chip contact length are then obtained through finite element simulation. In the temperature decrease phase, a temperature decrease model based on the one-dimension plate heat convection is proposed. A single wire thermocouple is employed to measure the tool temperature in the conducted milling experiments. Both of the theoretical and experimental results are obtained with cutting conditions of the cutting speed ranging from 60 m/min to100 m/min, feed per tooth from 0.12 mm/z to 0.20 mm/z, and the radial and axial depth of cut respectively being 4 mm and 0.5 mm. The comparison results show high agreement between the physical cutting experiments and the proposed cutting tool temperature prediction method.

Multi-Sensor Intelligent System for On-Line and Real-Time Moneitoring Tool Cutting State in FMS

The principle and the constitution of an intelligent system for on-line and real-time montitoring tool cutting state were discussed and a synthetic sensors schedule combined a new type fluid acoustic emission sensor (AE) with motor current sensor was presented. The parallel communication between control system of machine tools, the monitoring intelligent system,and several decision-making systems for identifying tool cutting state was established It can auto - matically select the sensor way ,monitoring mode and identifying method in machining process- ing so as to build a successful and effective intelligent system for on -line and real-time moni- toring cutting tool states in FMS.

Robustness evaluation of cutting tool maintenance planning for soft ground tunneling projects

Tunnel boring machines require extensive maintenance and inspection effort to provide a high availability.The cutting tools of the cutting wheel must be changed timely upon reaching a critical condition.While one possible maintenance strategy is to change tools only when it is absolutely necessary,tools can also be changed preventively to avoid further damages.Such different maintenance strategies influence the maintenance duration and the overall project performance.However,determine downtime related to a particular mainte-nance strategy is still a challenging task.This paper shows an analysis of the robustness to achieve the planned project performance of a maintenance strategy considering uncertainties of wear behavior of the cutting tools.A simulation based analysis is presented,imple-menting an empirical wear prediction model.Different strategies of maintenance planning are compared by performing a parameter vari-ation study including Monte-Carlo simulations.The maintenance costs are calculated and evaluated with respect to their robustness.Finally,an improved and robust maintenance strategy has been determined.