High Speed Machining Research Papers (original) (raw)

Recent improvements in machine and spindle designs have led to the increased use of high-speed machining (HSM) in the manufacture of discrete parts, especially in the aerospace industry . HSM seeks to increase depth of cut, and the corresponding material removal rate (MRR), through the selection of optimum cutting parameters. It is recognized that a major practical limitation on the productivity of HSM systems is regenerative chatter [2]. One method of pre-process chatter prediction and avoidance is the well-known stability lobe diagram. Stability lobe diagrams, which predict system stability as a function of selected machining parameters, are can used to select the best available spindle speed for maximized MRR. Stable and unstable regions (separated by the stability "lobes") are seen in these diagrams, depending on the selected spindle speed and axial depth of cut, b, for peripheral end milling.

- by
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- System Dynamics, Manufacturing Engineering, High Speed Machining, Machine

The effect of the radial rotor surface grooves on rotor losses, in the case of a 3-phase, 4-pole, 24000 rpm, axially slitted solid rotor induction motor has been studied numerically and experimentally. The study shows that through radial grooving of the rotor outer surface and thereby cutting the path for high frequency rotor harmonic currents results in considerable reduction of

- by Yoseph Gessese and +1
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- High Frequency, Finite Element Analysis, High Speed Machining, Conductivity

In this paper high speed turning and milling models are considered and chip formation and cutting forces are investigated. For the simulation the Finite Element Modeling software Third Wave Systems AdvantEdge is employed and the cutting forces results as well as the morphology of the chip are compared with the results of experiments conducted with CNC machine tools. For the experimental work the principles for design of experiment were used in order to minimize the required amount of experiments and obtain useful results at the same time. All parameters and cutting conditions were chosen to be close to the common industrial ones, with the material of the workpiece being C45 steel and the tools being coated carbides. Although published work on FEM simulations on high speed machining exist, this paper provides validated 3D models that cover the cases of precision high speed turning and high speed milling. The validation of the numerical data with the experimental ones show a good agre...

- by Dimitrios Manolakos
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- Finite Element Analysis (Engineering), High Speed Machining, Turning, Milling

This study shows the effects of aging on epoxy-based rapid tooling materials. Two epoxy-acrylate resins used for stereolithography and one aluminum powder-filled epoxy used for the high speed machining of plastic injection molds were selected to investigate their aging behavior in different environments. Four different conditions, each characterized by a specific relative humidity, were used to perform a seven week long aging study. Temperature was kept constant at 30°C. Both stereolithographic resins showed a drop in mechanical properties and in their glass transition temperatures in wet environments, whereas aging time showed little influence on these properties. Moisture uptake is mainly responsible for that drop and coefficients of water diffusion were determined. On the other hand, the aluminum powder-filled epoxy showed little humidity-dependent drop in mechanical properties and in its glass transition temperature during aging. This result correlates well with the very low moisture absorption of this material.

- by Xavier Ottemer
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- Mechanical Engineering, Rapid Prototyping, High Speed Machining, Injection Molding

Machine tool automation is an important aspect for manufacturing companies facing the growing demand of profitability and high quality products as a key for competitiveness. The purpose of supervising machining processes is to detect interferences that would have a negative effect on the process but mainly on the product quality and production time. In a manufacturing environment, the prediction of surface roughness is of significant importance to achieve this objective. This paper shows the efficacy of two different machine learning classification methods, Bayesian networks and artificial neural networks, for predicting surface roughness in high-speed machining. Experimental tests are conducted using the same data set collected in our own milling process for each classifier. Various measures of merit of the models and statistical tests demonstrate the superiority of Bayesian networks in this field. Bayesian networks are also easier to interpret that artificial neural networks.

- by Maritza Correa and +1
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- Machine Learning, Surface Roughness, Mathematical Sciences, High Speed Machining

The paper deals with analytical method of design and prediction of performance characteristics for induction motors with solid steel rotor coated with copper layer. On the basis of the distribution of the 2-D electromagnetic field, the equivalent impedance of the rotor has been derived. The edge effect and nonlinear magnetic permeability of solid steel have been included. The presented analytical method has been verified with laboratory test results. A 300 kW, 60 000-rpm, three-phase solid-rotor induction motor for the next generation air compressor has been investigated. The accuracy of analytical approach is acceptable and can be recommended for rapid design of solid-rotor induction motors.

- by Jacek F. Gieras
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- Engineering, Computer Science, Copper, IEEE

A model is presented of stationary shearing produced during the chip formation in orthogonal cutting. The work material is supposed to be a thermal sensitive viscoplastic rigid material. The effects of material parameters, of heat conductivity and of inertia on the distribution of strain rate and of temperature in the primary shear zone are analysed. The cutting forces are calculated for a large range of cutting speeds including high speed machining. The results are obtained by developing a simple one-dimensional modelling of the primary shear zone. Experimental measurements are compared with the theoretical results. Copyright ,~ 1996 Elsevier Science Ltd.

- by Alain Molinari
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- Mechanical Engineering, Civil Engineering, Strain Rate, Manufacturing Engineering

This work studies the cycle time prediction of high-speed milling for sculptured surfaces with high feed rates. Experiments and predictions were focused on representative surfaces of dies and molds, whose geometric complexity and complexity distribution were modified parametrically. CNC programs for machining these surfaces were executed in a HURON KX-10 machining center with a SIEMENS 840D controller, with different levels of programmed feed rate. Discrepancies between programmed and actual feed rates were evaluated. A mechanistic approach for cycle time evaluation in high-speed milling of sculptured surfaces is proposed. The mechanistic model construction is based on: (a) the frequency distribution (histogram) of linear interpolation path lengths in the CNC program and (b) a characterization of the machine tool for brisk (large changes in tool path direction) and smooth movements (small changes in tool path direction). Two case studies were used to demonstrate the effectiveness of the proposed approach (a set of representative sculptured surfaces with spherical caps and a forging die surface). Comparing the actual cycle time versus ideal cycle time under programmed feed rates up to 16 m/min, discrepancies of 300-800% were found. The proposed model is capable of predicting cycle time with a maximum error of 5-22%.

- by Horacio Ahuett and +1
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- Materials Engineering, Mechanical Engineering, Case Study, Manufacturing Engineering

Machining of titanium at high cutting speeds such as from 4 m/s to 8 m/s is very challenging. In this paper, a new generation of driven rotary lathe tool was developed for high-speed machining of a titanium alloy, Ti-6Al-4V. The rotary tool was designed and fabricated based on the requirements of compact structure, sufficient stiffness and minimal edge runout. Cylindrical turning experiments were conducted using the driven rotary tool (DRT) and a stationary cutting tool with the same insert, for comparison in the high-speed machining of Ti-6Al-4V. The results showed that the DRT can significantly increase tool life. Increase in tool life of more than 60 times was achieved under certain conditions. The effects of the rotational speed of the insert were also investigated experimentally. Cutting forces were found to decline slightly with increase of the rotational speed. Tool wear appears to increase with the rotational speed in a certain speed range. 

- by wenyu liu
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- Titanium, Experimental Design, Machine Tools, Manufacturing Engineering

An equation has been derived for the amplitude of the free surface displacement due to plane SH waves incident at any angle at the base of a layered crust. Numerical computations have been carried through for the case of a single-layered model of the continental crust. At any given angle of incidence the surface amplitude goes through a series of minima and maxima at periods which, in the single layered case, are harmonically related. At nearly grazing angles of incidence the surface amplitude is relatively small except at periods in the neighborhood of the cutoff periods of the second-and higher-order Love-wave modes.

- by In Sh
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- Geophysics, Multidisciplinary, Seismic Waves, Higher Order Thinking

Titanium alloys have been widely used in the aerospace, biomedical and automotive industries because of their good strength-to-weight ratio and superior corrosion resistance. However, it is very difficult to machine them due to their poor machinability. When machining titanium alloys with conventional tools, the tool wear rate progresses rapidly, and it is generally difficult to achieve a cutting speed of over 60 m/min. Other types of tool materials, including ceramic, diamond, and cubic boron nitride (CBN), are highly reactive with titanium alloys at higher temperature. However, binder-less CBN (BCBN) tools, which do not have any binder, sintering agent or catalyst, have a remarkably longer tool life than conventional CBN inserts even at high cutting speeds. In order to get deeper understanding of high speed machining (HSM) of titanium alloys, the generation of mathematical models is essential. The models are also needed to predict the machining parameters for HSM. This paper aims to give an overview of recent developments in machining and HSM of titanium alloys, geometrical modeling of HSM, and cutting force models for HSM of titanium alloys.

This tutorial is intended to guide the reader in the diagnostic analysis of acceleration signals from rolling element bearings, in particular in the presence of strong masking signals from other machine components such as gears. Rather than being a review of all the current literature on bearing diagnostics, its purpose is to explain the background for a very powerful procedure which is successful in the majority of cases. The latter contention is illustrated by the application to a number of very different case histories, from very low speed to very high speed machines. The specific characteristics of rolling element bearing signals are explained in great detail, in particular the fact that they are not periodic, but stochastic, a fact which allows them to be separated from deterministic signals such as from gears. They can be modelled as cyclostationary for some purposes, but are in fact not strictly cyclostationary (at least for localised defects) so the term pseudo-cyclostationary has been coined. An appendix on cyclostationarity is included. A number of techniques are described for the separation, of which the discrete/random separation (DRS) method is usually most efficient. This sometimes requires the effects of small speed fluctuations to be removed in advance, which can be achieved by order tracking, and so this topic is also amplified in an appendix. Signals from localised faults in bearings are impulsive, at least at the source, so techniques are described to identify the frequency bands in which this impulsivity is most marked, using spectral kurtosis. For very high speed bearings, the impulse responses elicited by the sharp impacts in the bearings may have a comparable length to their separation, and the minimum entropy deconvolution technique may be found useful to remove the smearing effects of the (unknown) transmission path. The final diagnosis is based on ''envelope analysis'' of the optimally filtered signal, but despite the fact that this technique has been used for 40 years in analogue form, the advantages of more recent digital implementations are explained.

With a significant progress achieved both in new cutting materials and in machine tool design, the weakest link in the machining system is, in many cases, the tooling structure serving as an interface between the cutting insert and the machine tool. lnadequacy of the tooling structure results in excessive static deflections limiting the achievable accuracy, and in forced and self-excited vibrations limiting the cutting regimes and surface finish of the machined surface. In order to advance the tooling structures' technology, it is important to assess the state of the art, keeping in mind that the majority of publications on the subject is not in English. This paper provides a worldwide analytical survey on six important subjects related to tooling structures: ?) Influence of machining system parameters on tool life and process stability; 2) Stiffness and damping of tools; 3) Tool/toolholder interfaces (tool clamping devices); 4) Modular tooling; 5) Tool-machine interfaces; 6) Tool balancing for high speed machine tools Keywords: tooling; stiffness; damping; t tHTRUWTtOH tool and the workpiece. it was suggested by W a l k , e t a/ (1991) to imptmt into the cutting surface atoms o f elements CI, Br, I, S, In, Ga, Sn. These elements are routinely used in lubricoo[ant fluids, especially for machining titanium alloys. tubricootants containing these etements sometimes cause corrosion, but their implantation to the depth of about 0.4 pm resutts M reduced friction and cutting forces and increased t o d life, without degrading the surface finish. A similar technique proposed by Pleshivtsev, et a1 (1994) results in 20 -30 % reduction in friction coefficient of HSS inserts while increasing their life by twotothree times. This implantation is performed by gas ion generators with or without magnetic field. The ion pulse length is 1 -7,500 ms, pulse energy 10 -80 Kev, and current t -60 A. 592 Keynote Papers tntroductton of uttra-high pressure (70 -280 MPa) wafer info the cuffing zone reduces the axial cuffing fmee by 5ooh while impwing 0 t h machining parameters, Mazclrkievfcz (7992). Even higher pressures, up to 380 MPa, were sumessftltty used by Cornier (1992).

Nickel-based high temperature alloys have excellent physical properties, which make them ideal for use in the manufacture of aerospace components. However, they exhibit poor machinability. Though conventional machining in industries is currently being carried out using carbide tools, there is little scope for improving the material removal rate. Machining, being a major operation, needs to be improved in order to reduce the throughput time. High Speed Machining (HSM) is a promising technique for increasing productivity in this regard. This paper mostly reviews research and development work in the machining of nickel-based high temperature alloys carried out over the last 15 years with the objective of assessing the present scenario. Emphasis is laid on Inconel 718, which is most commonly used. Both turning and milling operations using conventional and High Speed (HS) machining are reviewed herein. HSM is discussed at length in comparison with conventional machining, as it is possible to drastically improve material removal rate using HSM. In addition to the study of insert materials and tool geometry, other aspects affecting HSM are also discussed. Surface integrity of Inconel 718 obtained through HSM and the recently developed technique of Plasma Enhanced Machining (PEM) is also addressed.

The Research paper entitled above gives trace on Simulation Model for Teaching and Learning. This is the important area in which the teaching and learning can be benefited. The teaching methods involve three types of methods like lecturing method; Computer based teaching method and mixed teaching methods. The researcher has studied the methods used by teachers and method preferred by the students they have also returned the rules to find out the quality of the teaching and learning. The results are found by Chi. Square test for the teaching and learning methods. The respondents taken for the study were 100 teachers and students were 100. The final results are very surprising and it suggests using both Computers based and lecturing method of teaching learning process. The simulation model is designed by the researcher to find out the best method of the teaching and learning process in higher education. The main objective of the paper is to trace on the best method of the teaching and learning so that the output of the teaching method is improved and students are benefited by this. The objectives of this paper are to study various types of teaching and learning methods used by higher educational Institutes, study the ideas and the best way of teaching suggested by expert teachers, to study the ideas of students who are good in learning and to develop a simulation model and verify using 100 examples for teaching and learning.

- by afaque memon
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- High Speed Machining

- by Pete Harrell
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- Construction, Control Systems, Control system, Natural Gas

This paper introduces a novel parallel kinematic mechanism (PKM) machine called Cartesian-Guided Tripod (CGT) developed for high-speed machining of precise dies and molds. CGT has two kinds of functional independent legs, the driving functional leg and the integrated Cartesian guiding/metrology functional leg, parallel-linked to the platform. The guiding/metrology functional leg constraints and measures the platform motions in Cartesian coordinates. Because of the separation of metrology function from the drive mechanisms, the metrology loop of CGT is immunized to the geometric-, thermal-, and force-induced errors of the drive mechanisms. Another feature of this CGT is that the kinematic parameters can be auto-calibrated on line. CGT has explicit solutions of the inverse and forward kinematic analysis. This allows system specifications, such as the footprint/workspace ratio, maximum Cartesian speed/acceleration and even stiffness, be easily related to the machine component specifications. The CGT drive mechanism can be divided into two basic types: sliding leg and telescoping leg. The telescoping leg CGT has the higher edges in the kinematic categories than the sliding leg CGT. Conversely, the sliding leg CGT has better static rigidity and dynamic stiffness than the telescoping leg CGT.

- by Aaron Hsu
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- Engineering, Technology, High Speed Machining, Physical sciences

ABSTRAK Umur pahat merupakan suatu data permesinan yang sangat penting dalam perencanaan permesinan. Setiap perusahaan yang bergerak dibidang manufaktur pasti mempunyai batas tertentu untuk umur pahat optimal agar perencanaan pemesinan menjadi terarah. Namun pada praktik di lapangan , umur pahat aktual pada mesin High speed machining di PT.Dirgantara Indonesia tidak sesuai dengan batas optimal yang ditetapkan perusahaan. Dalam penelitian ini akan mengamati dan menghitung umur pahat aktual yang terjadi pada proses pemesinan. Penelitian ini dilakukan dengan membandingkan data kondisi pemesinan teoritis dengan data kondisi pemesinan aktual yang didapat di lapangan, kemudian menentukan apakah secara actual umur pahat sudah mencapai nilai optimal yang ditetapkan perusahaan. Jika belum optimal, akan dilakukan perhitungan nilai kondisi pemesinan yang ideal agar umur pahat mencapai nilai optimal. Kondisi pemesinan yang dapat diamati adalah kecepatan spindel , kecepatan makan , kecepatan potong dan daya mesin. Pengamatan dilakukan terhadap pahat slot drill berdiameter 25 mm pada pembuatan closing rib dengan menggunakan mesin CNC DMC 210 U. Dari hasil penelitian didapat bahwa umur aktual dari slot drill adalah 330,453 menit , lebih kecil dari umur pahat optimal yang telah ditetapkan yaitu 350 menit. Sehingga dilakukan perhitungan kondisi pemesinan untuk pahat slot drill agar umur pahat mencapai 350 menit. Dari hasil perhitungan didapat bahwa agar pahat mencapai 350 menit , kecepatan potong harus diturunkan menjadi 1224,367 mm/min , kecepatan spindle harus diturunkan menjadi 15600 rpm rpm, feed rate diturunkan menjadi 4680 mm/min, material removal rate menjadi 234 cc/min dan daya yang dihasilkan menjadi 3,82 Kw. Kata Kunci : High speed machining, slot Drill , Mesin DMC 210 U, umur pahat, kondisi pemesinan. 1. PENDAHULUAN Teknologi pemesinan kecepatan tinggi (high speed machining) merupakan salah satu cara untuk meningkatkan produktivitas dengan kecepatan potong yang tinggi, maka volume pelepasan material dari material induk akan meningkat sehingga akan diperoleh penghematan waktu pemesinan yang cukup berarti. Teknologi pemesinan kecepatan tinggi (high speed machining) biasanya didefinisikan berdasarkan kecepatan spindle mesin yang kecepatannya diatas 18.000 putaran per menit (rpm). Mesin kecepatan tinggi yang digunakan PT. Mesin kecepatan tinggi biasa digunakan dalam proses pemesinan bagian-bagian dari pesawat seperti titanium, aluminium dan nikel paduan. Salah satunya terdapat pada PT. Dirgantara Indonesia, dimana penggunaan high speed machining menjadi salah satu pokok utama dalam proses pemesinan dalam pembuatan bagian pesawat. Dirgantara Indonesia adalah mesin CNC canggih generasi lima yaitu DMG Mori DMC 210U buatan Jerman yang merupakan mesin CNC yang memiliki 5 axis. Mesin ini memiliki kecepatan putar maksimal sebesar 30.000 rpm dan meja kerjanya dapat menahan berat benda kerja sampai 6000 kg, sangat sesuai untuk pembuatan bagian pesawat yang mempuqnyai ukuran yang cukup besar. Namun dalam aplikasinya, mesin DMG Mori DMC 210U ini masih belum dapat bekerja secara maksimal. Salah satu penyebabnya adalah penggunaan cutting tool yang belum optimal. Disini penulis mengangkat judul tersebut untuk mendapatkan nilai optimal dari sebuah cutting tool. Penulis tertarik mengangkat judul tersebut dikarenakan di PT Dirgantara Indonesia cutting tool yang belum aus sudah di ganti dan kemudian di tajamkan kembali dan digunakan kembali tanpa melihat nilai optimal sebenarnya dari cutting tool itu sendiri. Untuk mendapatkan nilai optimal dari cutting tool tersebut penulis mengambilkan pembanding yaitu kecepatan potong, kecepatan spindle, feed rate, material removal rate, dan daya mesin aktual dari salah satu cutting tool yang di pakai pada saat proses pembuatan closing rib pesawat Airbus 320 langsung dari mesin DMG Mori DMC 210U yang akan di bandingkan dengan data teoritis yang sudah dipakai di PT Dirgantara Indonesia. Dengan di dapatkannya nilai optimal dari salah satu cutting tool nantinya dapat berdampak pada optimalisasi mesin dan umur dari cutting tool itu sendiri.

- by anugrah lofty
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- High Speed Machining

High speed machining (HSM) is an outstanding technology capable of improving productivity and lowering production costs in manufacturing companies. Drilling is probably the machining process most widely applied to composite materials; nevertheless, the damage induced by this operation may reduce drastically the component performance. This work employs HSM to realize high performance drilling of glass fibre reinforced plastics (GFRP) with reduced damage. In order to establish the damage level, digital analysis is used to assess delamination. A comparison between the conventional (F d ) and adjusted (F da ) delamination factor is presented. The experimental results indicate that the use of HSM is suitable for drilling GFRP ensuring low damage levels.

- by Juan Rubio
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- Productivity, Manufacturing Engineering, High Speed Machining, Drilling

High speed machining of low rigidity structures is a widely used process in the aeronautical industry. Along the machining of this type of structures, the so-called monolithic components, large quantities of material are removed using high removal rate conditions, with the risk of the instability of the process. Very thin walls will also be milled, with the possibility of lateral vibration of them in some cutting conditions and at some stages of machining. Chatter is an undesirable phenomenon in all machining processes, causing a reduction in productivity, low quality of the finished workpieces, and a reduction of the machine-spindle's working life.

- by F. Campa and +1
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- Manufacturing Engineering, High Speed Machining, Dimensional, High Speed

Investigation of tool wear in High Speed Machining (HSM) by using a ballistic setup is proposed. An originality of this work consists in analyzing the previous models in sight of the real temperatures fields measured during the cutting process. Results show the high potentiality of the presented device associated with wear modeling. The chip formation and the temperature distribution are observed in real time under perfect orthogonal cutting conditions at very high cutting speeds with an intensified CCD camera. Observations highlight the importance of the evolution of the tool-chip contact during the crater wear process, especially when low feeds are selected. For low feeds, the crater profile seems control the rollingup of the chip which also participates to accentuate the wear. Experimental results such as temperature distribution and contact length are input into diffusion wear models under different assumptions for predicting the evolution of crater profiles. Taking into account the mechanical action of the chip on the tool rake face, the prediction of tool wear is reached with a great accuracy.

- by Gustavo Sutter
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- Materials Engineering, Mechanical Engineering, Wear, Tool wear

Despite the large number of abrasive waterjet machining (AWJM) models developed so far, there still has been confusion about the nature by which workpiece surfaces are eroded. The finite element method (FEM) could provide both qualitative and quantitative means in order to explain the AWJ erosion process. This paper presents an attempt to model the AWJM process using the powerful tool of the finite element method. The main objective is to develop an FE model which would enable to predict the depth of cut without any cutting experiments. The new model takes into account the precise representation of the constitutive behaviour of the workpiece material under AWJ dynamic loading conditions. Interaction of the abrasive particle with the workpiece material is traced at small time increments. The model accurately predicts the depth of cut as a result of AWJ impact and the results are in good agreement with experimental results.

MoS coatings have been proposed for improvement in the performance of cutting tools, and such coatings have been shown to 2 w x give significant improvements Rechberger J, Brunner P, Dubach R. Surf Coatings Technol 1993;62:393᎐398 . Recently, new MoS based coatings have been developed, combining very low friction with high hardness, very high wear resistance and high 2 Ž

- by Nathalie M Renevier
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- Titanium, High Speed Machining, Materials Design, Wear resistance

Abstract: Pythagorean--hodograph (PH) curves admit the formulation ofreal--time CNC interpolators that are extremely accurate, flexible,and robust. Motivated by the practical benefits of these algorithmsin high--speed machining applications, we study the approximationof "traditional" (piecewise--linear/circular) G code part programsby PH curve tool paths. A least--squares fitting approach, entailingthe solution of a non--linear system of equations in four variables, isemployed to accomplish ...

- by Kazuhiro Saitou
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- The history of mathematics, High Speed Machining, Piecewise Linear, High Speed

Titanium alloys are used for the manufacturing of femoral heads for orthopaedic implants. Poor machinability of these materials, especially at high speeds, creates the need for more detailed investigations on this subject. The at hand study analyzes the construction of 3D Finite Element Method (FEM) models pertaining to the manufacturing of femoral heads made from Ti-6Al-4V. For this purpose a commercial FEM programme is employed, specialising in machining modelling, namely AdvantEdge. The validation of the model is provided through experiments on actual femoral heads cut in a CNC lathe at high cutting speeds. Comparison between experimental and numerical results on cutting forces and chip morphology exhibits a good agreement, indicating the success of the proposed models. These 3D models can be used for realistically estimating the influence of cutting conditions on the final product, without performing time and money consuming experiments.

- by Dimitrios Manolakos and +2
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- High speed machining of titanium, Finite Element Analysis (FEA), 3d Modelling, High Speed Machining

Tool condition monitoring, mainly tool breakage detection for high-speed machining (HSM), is an important problem to solve; however, the techniques or types of sensors applied in other research projects present certain inconveniences. In order to improve tool breakage monitoring systems, a simple, effective, and fast method is presented herein. This method is based on the discrete wavelet transform (DWT) and statistical methodologies. The effectiveness of the method is based on the measurements of the feed-motor current signals using inexpensive sensors. It is well-known that during the cutting process, the motor current is related to the tool condition. The current consumption changes when the tool is broken as compared to when the tool is in normal cutting condition. This difference can be obtained from the waveform variances between the signals in order to ascertain the tool condition. The algorithms of this research project consist of obtaining compressed signals from the I rms feed-motor current signals applying the DWT. Then from these compressed signals, we detect the asymmetries between them. The arithmetic mean value is applied to asymmetries of consecutive machining lengths to reduce noise in the data having a mean value of a series of asymmetries; also, a normal cutting threshold is set up in order to make decisions regarding the tool conditions so as to detect tool breakage. Therefore, this research project shows a low-cost monitoring system that is simple to implement.

- by Juan Jauregui
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- Engineering, Condition Monitoring, Mathematical Sciences, Wavelet Transform

Automated Tape Laying and Fiber Placement of composite materials are the two principal automated processes used for fabrication of large composite structures in aeronautical industry. The aluminum parts produced by High Speed Machining tend to be replaced by carbon fiber composite parts realized with these processes. However, structural parts present reinforcement zones which disturb the tool path follow-up and generate an increase of the manufacturing time. Thus, this paper deals with the optimization of tool paths of a 7-axis machine tool of Fiber Placement with the objective of reducing the manufacturing time while ensuring the requested quality of the final part. In this paper, two complementary methods are detailed. The first method takes advantage of the degree of redundancy of the machine tool to decrease the kinematic loads of the control joints. The second method aims to smooth the orientation of the machine head along the tool path while ensuring quality constraints. These two methods are then applied on a test tool path and bring to a significant decrease of the manufacturing time (32.9%).

Abstract: This paper deals with simulation models allowing predictions of the surface finish and the actual velocity during machining. To simulate material removal in 5-axis machining, we propose an N-buffer based model integrating the Inverse Kinematics Transformation. This model can be coupled with the NC-simulation model we have previously developed, and which has been validated for several sets of NC/machine tools. The tooth track is thus linked to the velocity giving the surface topography resulting from actual machining.

- by Sylvain Lavernhe and +1
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- High Speed Machining

In this research, we investigated the performance of polished chemical vapor deposited (CVD) diamond tool carbide inserts in comparison with unpolished CVD diamond coated carbide tool inserts in the dry turning of A390 aluminum-silicon hypereutectic alloy. The special emphasis is on exploring the role of machining parameters and cutting tool surface morphology on the aerosol generation. Global demand for high speed machining in combination with environmentally benign methods make diamond coated carbide tools an attractive candidate for dry machining. The results of this research demonstrate that CVD diamond-coated polished tools generate fewer particles, unlike conventional diamond tools (PCD and unpolished CVD), which cause the formation of respirable airborne particles during machining. Further, polished CVD diamond tool inserts improve tool life and reduce the cutting forces. Overall, in an important finding it is shown that polishing of tools provides a better opportunity for an environmentally benign dry machining along with improvement in machining outcome.

- by Prabhu Arumugam
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- Materials Engineering, Condensed Matter Physics, High Speed Machining, CVD

The compliance effect of a high-speed ballscrew feed-drive system is modelled in this work. A mechanical model of a ball-screw feed drive system including the motor, ball-screw, coupling, supporting bearing, linear guide and machine structure was developed. It was found that at high acceleration, the mechanical compliance caused a significant contouring error. Smoothing the acceleration and deceleration control input command did improve the transient deviation in the contouring error. However, the steady state error caused by the elastic elongation in the mechanical elements was not improved. It was also shown that the inertia force of the slide and saddle comprised the dominant loading on a high speed machine tool drive mechanism. A topology structure optimisation method is proposed to reduce the moving weight. This method can help the designer efficiently reduce the moving weight of a machine tool axis in a systematic way. More than a 30% weight reduction was demonstrated in a spindle carrier structural design.

- by Yikun Huang and +1
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- Engineering, Structural Design, Mathematical Sciences, High Speed Machining

Abstract The present paper outlines an experimental study to investigate the effects of cutting parameters on finish and power consumption by employing Taguchi techniques. The high speed machining of AISI 1045 using coated carbide tools... more

High speed machining has been made possible but its complete utilization is at stake because for the lack of proper lubricant and/or coolant that would help in quick transfer of heat and safe guard the component from thermo-mechanical failure. Liquid nitrogen can be proved to be the most suitable solution to this problem that is not only efficient but also economical.

- by VIJAYVIGNESH N S
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- Cryogenics, Heat Transfer, Machining, Grinding

Two new coatings based on graphite and MoS 2 have been developed. They combine low friction with high hardness, high load capacity and exceptionally low wear. Both coatings act as solid lubricants, providing protection for both the coated surface and any opposing uncoated surface. The coatings are finding application in improving the general performance of cutting and forming tools and also make possible high-speed machining. The graphite-based coatings have exceptional wear properties under water or oil and results from wear tests under a wide range of conditions are given. A number of practical applications are given, including the protection of artificial hip joints. The advantages offered by the use of such coatings for many mechanical components are demonstrated.

New carbon-based nanostructured composite coatings of the material system Ti-Al -N -C were deposited on cemented carbide milling tools, and their feasibility for selected dry highspeed machining operations was assessed. For this purpose, wear studies with instrumented cutting machines in dry cutting tests were carried out in milling operations on Uddeholm hardened steels (AISI H13, and, AISI A2, respectively). The tools were coated in an industrial sputtering machine of the Hauzer HTC 625 type. The new nanocomposite coatings showed a good performance in the dry cutting operations and were benchmarked versus industrial stateof-the-art coatings.

- by Carlos Ziebert
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- Manufacturing Engineering, High Speed Machining, Magnetron Sputtering

An original method for measuring dynamic forces using a commercial piezoelectric dynamometer is presented. This approach is based on the construction of a correction function taking into account the dynamic behavior of the mechanical... more

- by Luís Castro
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- Modal Analysis, Manufacturing Engineering, High Speed Machining, Machine

This paper describes the experimental procedure to identify the predominant frequencies of the high speed testing machine by conducting modal analysis. The effects due to the predominant frequencies of the system and loading rate on the magnitude of system ringing and the flow stress were analyzed by using a single degree-of-freedom (SDOF) spring-mass-damper model. The system was then used to study the dynamic tensile behavior of two engineering materials, i.e., polyethylene (PE) fabric-cement composite and Alkaline Resistant (AR) glass fabrics at an intermediate strain rate. The stress oscillations in the response of these materials due to system ringing were addressed. The failure behavior of each material was studied by examining high speed digital camera images of specimens during the test. The validity of the dynamic tensile tests was investigated by examining the condition of dynamic stress equilibrium—a criterion used in split Hopkinson pressure bar (SHPB) tests. The results ...

- by Barzin Mobasher
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- Mechanical Engineering, Civil Engineering, Experimental Mechanics, Modal Analysis

High-speed machining is a milling operation in industrial production of aeronautic parts, molds, and dies. The parts production is being reduced because of the slowing down of the machining resulting from the tool path discontinuity machining strategy. In this article, we propose a simulation tool of the machine dynamic behavior, in complex parts machining. For doing this, analytic models have been developed expressing the cutting tool feed rate. Afterwards, a simulation method, based on numerical calculation tools, has been structured. In order to validate our approach, we have compared the simulation results with the experimental ones for the same examples. Keywords Machining . Pocket . Modeling . Simulation . HSM Instantaneous feed Jerk J ! Jerk vector J t Tangential Jerk J c Normal Jerk J max Maximal Jerk J max i Maximal Jerk of axis (i) J curv Curvilinear tangential Jerk J tcurv Tangential Jerk on curvature r jct

- by M. Baili and +1
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- Engineering, Modeling and Simulation, Mathematical Sciences, High Speed Machining

CrAlYN/CrN coatings represent a new generation Ti-free PVD coatings tailored to serve high temperature applications such as dry high speed machining and protection of special grades aerospace and automotive alloys against environmental attack. The novel High Power Impulse Magnetron Sputtering (HIPIMS) technique was used for substrate pre-treatment (etching) followed by coating deposition utilising Unbalanced Magnetron Sputtering (UBM). The employment of HIPIMS resulted in smooth (R a = 0.036 μm) and well adherent films with typical scratch adhesion critical load values on M2 high speed steel of L C = 65 N. Low-angle XRD analysis showed that the coating has a nanoscale multilayer (superlattice) structure with a typical bi-layer thickness of 4 nm. XTEM observations confirmed this result and further revealed the dense, growth defect free structure of the coating due to the HIPIMS etching. CrAlYN/CrN combines high hardness of HK 0.025 = 3320 with a low coefficient of friction of 0.5 and an exceptionally low sliding wear coefficient of 3.7 × 10 − 17 m 3 N − 1 m − 2 , which is comparable to that of TiAlN/VN and Me-Carbon films. In dry high speed milling (V cutting = 385 m min − 1 ) of hardened A2 tool steel (HRC = 58), 8 mm cemented carbide ball nosed end mills coated with CrAlYN/CrN outperformed TiAlCrYN, which is one of the market leading coatings dedicated to this application. When the test is carried out at the higher end of the cutting speed range of 500 m min − 1 this difference in performance becomes even more pronounced (factor of 8 longer life time), which demonstrates the excellent quality of CrAlYN/CrN.

The paper reports the findings of the experimental work to study the impact of machining parameters, particularly cutting speed, feed rate, and axial depth of cut towards cutting tool life and machined surface roughness in high-speed milling aluminium alloy 7075-T6 with bullnose cutter under dry environment. Previous studies found that tool life and surface roughness in machining aluminium alloy 7075-T6 using cemented carbide are unfavourable compared to other materials. However, this observation needs further study. Thus, a raw block of aluminium alloy 7075-T6 was proposed in this experiment. An eight-run experiment was designed according to full factorial design based on two levels of cutting speed (500 m/min, 600 m/min), feed rate (0.12 mm/tooth, 0.15 mm/tooth), and axial depth of cut (1.40 mm, 1.70 mm) and then analysed employed ANOVA. Cutting tool life was restricted by tool wear in the milling process. The microscope and portable surface roughness tester were employed to analyse tool wear and average surface roughness value. Cutting speed and feed rate were found to be a significant factor to the tool life and surface roughness. The longest tool lifespan of 16.79 minutes and lowest surface roughness value of 0.595 µm were determined at a speed of 500 and 600 m/min, respectively, with a low combination of the rest of parameter, which are 0.12 mm/tooth and 1.40 mm.

- by Azreen Zainol
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- High Speed Machining, 7075 Aluminum Alloy
- by S. Ekinović
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- Materials Science, Productivity, Machining, Surface Roughness

The U.S. natural gas pipeline industry is facing the twin challenges of increased flexibility and capacity expansion. To meet these challenges, the industry requires improved choices in gas compression to address new construction and enhancement of the currently installed infrastructure. The current fleet of installed reciprocating compression is primarily slow-speed integral machines. Most new reciprocating compression is and will be large, highspeed separable units. The major challenges with the fleet of slow-speed integral machines are: limited flexibility and a large range in performance. In an attempt to increase flexibility, many operators are choosing to single-act cylinders, which are causing reduced reliability and integrity. While the best performing units in the fleet exhibit thermal efficiencies between 90% and 92%, the low performers are running down to 50% with the mean at about 80%. The major cause for this large disparity is due to installation losses in the pulsation control system. In the better performers, the losses are about evenly split between installation losses and valve losses. The major challenges for high-speed machines are: cylinder nozzle pulsations, mechanical vibrations due to cylinder stretch, short valve life, and low thermal performance. To shift nozzle pulsation to higher orders, nozzles are shortened, and to dampen the amplitudes, orifices are added. The shortened nozzles result in mechanical coupling with the cylinder, thereby, causing increased vibration due to the cylinder stretch mode. Valve life is even shorter than for slow speeds and can be on the order of a few months. The thermal efficiency is 10% to 15% lower than slow-speed equipment with the best performance in the 75% to 80% range. The goal of this advanced reciprocating compression program is to develop the technology for both high speed and low speed compression that will expand unit flexibility, increase thermal efficiency, and increase reliability and integrity. Retrofit technologies that address the challenges of slow-speed integral compression are: (1) optimum turndown using a combination of speed and clearance with single-acting operation as a last resort; (2) if single-acting is required, implement infinite length nozzles to address nozzle pulsation and tunable side branch absorbers for 1x lateral pulsations; and (3) advanced valves, either the semi-active plate valve or the passive rotary valve, to extend valve life to three years with half the pressure drop. This next generation of slow-speed compression should attain 95% efficiency, a three-year valve life, and expanded turndown. New equipment technologies that address the challenges of large-horsepower, high-speed compression are: (1) optimum turndown with unit speed; (2) tapered nozzles to effectively reduce nozzle pulsation with half the pressure drop and minimization of mechanical cylinder stretch induced vibrations; (3) tunable side branch absorber or higher-order filter bottle to address lateral piping pulsations over the entire extended speed range with minimal pressure drop; and (4) semi-active plate valves or passive rotary valves to extend valve life with half the pressure drop. This next generation of large-horsepower, high-speed compression should attain 90% efficiency, a two-year valve life, 50% turndown, and less than 0.75 IPS vibration. This program has generated proof-of-concept technologies with the potential to meet these ambitious goals. Full development of these identified technologies is underway. The GMRC has committed to pursue the most promising enabling technologies for their industry.

- by Pete Harrell
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- Construction, Control Systems, Control system, Natural Gas

The growing interest in predictive maintenance makes industrials and researchers turning themselves to artificial intelligence methods for fulfilling the tasks of condition monitoring and prognostics. Within this frame, the general purpose of this paper is to investigate the capabilities of an Evolving eXtended Takagi Sugeno (exTS) based neuro-fuzzy algorithm to predict the tool condition in high-speed machining conditions. The performance of evolving Neuro-Fuzzy model is compared with an Adaptive Neuro-Fuzzy Inference System (ANFIS) and a Multiple Regression Model (MRM) in term of accuracy and reliability through a case study of tool condition monitoring. The reliability of exTS also investigated.

- by R. Gouriveau and +1
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- Condition Monitoring, Case Study, Tool wear, High Speed Machining

Purpose: The aim of this research is to make a first experimental analysis of the effect of the cutting speed on the chip morphology, and of the cutting forces in the orthogonal turning process of the titanium alloys Ti-6Al-4V. Design/methodology/approach: The methodology has consisted of proving a series of parameters combinations: f, feed rate, Vc, cutting speeds are explored in a range from 50 to 250 m/min, and is analyzing the different types of chips and the evolution cutting forces appeared during each one them, and determined the analytical model of plastic deformation ratio. Findings: Tests achieved have shown three main types of chips: Continuous chip at 50 m/min, Flow chip for speeds ranging around 100 m/min, and Shear localized chip starting from the transition speed of 125 m/min and above. The modification of the mechanism of chip formation is associated with the appearance of shearing instability. Chip segmentation by shear localisation is an important process which is ...

- by A. Daymi
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- Titanium, Automotive Industry, Shear bands, High Speed Machining

In high-speed machining there are a number of applications in which the spindle is supported by air bearings. This type of bearings has very low friction and wear, resulting in virtually unlimited life. If the system is designed correctly... more

- by G. Belforte
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- Applied Mathematics, High Frequency, High Speed Machining, Mathematical Model

Les machines-outils d'usinage et de travail à grande vitesse (UTGV) doivent atteindre un niveau de performance donné en terme de précision et de rigidité statique et dynamique. Leur dimensionnement nécessite la considération des flexibilités ainsi que de la stratégie de commande adoptée. Dans cet article nous présentons une approche de modélisation dynamique de mécanismes flexibles en vue de leur commande et dimensionnement pour des applications de type UTGV. Pour formuler le modèle cinématique d'un manipulateur flexible, les opérateurs de déplacements infinitésimaux sont utilisés. Les termes de déplacements infinitésimaux d'ordre supérieur à 1 sont systématiquement négligés. Les équations du mouvement sont par la suite obtenues en utilisant le formalisme de Lagrange. L'approche proposée permet de traiter les deux cas de flexibilités distribuées et localisées. L'importance de la prise en compte de la flexibilité est illustrée par des résultats de simulation, pour un prototype de machine UTGV à architecture cinématique parallèle, dans le cas de flexibilités localisées.  2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.

- by B. Bouzgarrou
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- Modeling, Dynamics, Kinematics, High Speed Machining