Metal Cutting

This paper presents a study for the development of first- and second-order tool-life models at 95% confidence level for turning high strength steel. The tool-life models are developed in terms of cutting speed, feed rate, and depth of cut, using response surface methodology and design of experiment. The effects of the main cutting variables (cutting speed, feed, and depth of cut) on tool life have been investigated by the application of the factorial design method. All of the cutting tests were performed using uncoated carbide tools under dry conditions. Tool-life contours have been generated from these model equations and are shown in different plots. Dual-response contours of metal removal rate and tool life are shown also. The results are presented in terms of mean values and confidence levels. © 1998 Elsevier Science S.A. All rights reserved.

https://ac.els-cdn.com/S0924013697004354/1-s2.0-S0924013697004354-main.pdf?_tid=7ea8c4dc-1d34-11e4-b1a5-00000aab0f6c&acdnat=1407307382_b0d7d5d96bfabc738bde8c6860d2acd2 
https://www.sciencedirect.com/science/article/pii/S0924013697004354

In 5-axis tool path generation the tool axis is usually selected based on the workpiece geometry only, ignoring its effects on the process and machine tool motion. In this paper, a process simulation integrated tool axis selection approach is proposed to adjust the tool axis vectors in an already generated 5-axis milling path for improved process in terms of cutting forces, stability and machine tool motion. The part surface data, required to re-calculate the tool axis, is extracted from the existing path. The proposed approach is demonstrated on a representative case.

The increasing attention to the environmental and health impacts of industrial activities by governmental regulations and by the growing awareness level in the society is forcing industrialists to reduce the use of mineral oil-based metalworking fluids as cutting fluid. Cutting fluids have been used extensively in metal cutting operations for the last 200 years. In the beginning, cutting fluids consisted of simple oils applied with brushes to lubricate and cool the machine tool. As cutting operations became more severe, cutting fluid formulations became more complex. There are now several types of cutting fluids in the market and the most common types can be broadly categorized as cutting oils or water-miscible fluids. In this review, the applicability of vegetable oil-based metalworking fluids in machining of ferrous metals has been undertaken. The advantages of metalworking fluids and its performances with respect to the cutting force, surface finish of work piece, tool wear and temperature at the cutting zone have been investigated. It has been reported in various literature that metalworking fluids, which are vegetable oil-based, could be an environmentally friendly mode of machining with similar performance obtained using mineral oil-based metalworking fluids. © 2011 Elsevier Ltd. Allrightsreserved.

https://ac.els-cdn.com/S0890695511001726/1-s2.0-S0890695511001726-main.pdf?_tid=264eeadc-1d34-11e4-ae6e-00000aacb35f&acdnat=1407307234_34c85dbb762d33f91af7172058226f2e 
https://www.sciencedirect.com/science/article/pii/S0890695511001726

In this work optimization of turning parameters for turning Ti-6Al-7Nb Titanium alloy has been investigated by orthogonal array along with Grey relational analysis coupled with principle component. Parameters such as surface roughness, tool wear, roundness, material removal rate, temperature and power consumption are considered as performance characteristics of the turning process. By orthogonal array eighteen experiments are carried out in the CNC machine by considering cutting environment, cutting speed, feed rate, depth of cut, nose radius, tool coating type and insert shape angle as turning parameters. From the grey relational grade the optimum turning parameters were predicted. Also the influence of individual turning parameters is carried out by Analysis of Variance. From the largest value of grey relational grade parameters , cutting environment: wet, feed rate : 0.08 mm /rev, cutting speed: 100 m/min ,insert angle: 80 0 , nose radius: 0.4 mm, tool coating type : TiAlN and depth of cut:0.4 mm are found to be better turning parameters levels. About 11.3 % enhancement of grey relation grade value is achieved when compared to initial parameter grey relational grade value.

This paper outlines the Taguchi optimization methodology, which is applied to optimize cutting parameters in end milling when machining hardened steel AISI H13 with TiN coated P10 carbide insert tool under semi-finishing and finishing conditions of high speed cutting. The milling parameters evaluated are cutting speed, feed rate and depth of cut. An orthogonal array, signal-to-noise (S/N) ratio and Pareto analysis of variance (ANOVA) are employed to analyze the effect of these milling parameters. The analysis of the result shows that the optimal combination for low resultant cutting force and good surface finish are high cutting speed, low feed rate and low depth of cut. Using Taguchi method for design of experiment (DOE), other significant effects such as the interaction among milling parameters are also investigated. The study shows that the Taguchi method is suitable to solve the stated problem with minimum number of trials as compared with a full factorial design. © 2003 Elsevier B.V. All rights reserved.

https://ac.els-cdn.com/S0924013603008653/1-s2.0-S0924013603008653-main.pdf?_tid=2237c70c-1d34-11e4-be23-00000aab0f02&acdnat=1407307227_44583f52d51574fb6af1f7e09c9ed31b 
https://www.sciencedirect.com/science/article/pii/S0924013603008653

With high speed of technology development, Plasma CNC machine plays an important role in industry, as it can cut any metal using only compressed air ignited at high voltage and high frequency. The cut is fast, clean and highly accurate. This report shows how plasma CNC machine was built step by step. Plasma CNC machine contains several parts: plasma unit, controller circuit, CNC table and software. Plasma unit generates the plasma torch which can cut the metals. Controller circuit controls the stepper motors using microstepping method. This method has high accuracy control. CNC table design and analysis was performed by Autodesk Inventor software. CNC table contains three axes Y-axis, X-axis, Z-axis which move using rods and rails as linear motion system. It is strong and stable. Plasma trace Software was used to convert images to G-code that will be loaded to MACH3 software and mach3 will send commands to controller circuit by parallel port to move the axes. The plasma CNC machine was tested and gave good results with high accuracy.

Machinability assessment of nickel base super alloy (inconel 718) in turning operations has been carried out using coated and uncoated carbide inserts under dry conditions. Inconel 718 is one of the most difficult-to-machine materials because of its low thermal diffusive ...

The power consumed in metal cutting is largely converted into heat. Several attempts have been made to predict the temperatures involved in the process as a function of many parameters, as well as many experimental methods to measure temperature directly. Some simple analytical models can be used to show the effects of cutting parameters, such as cutting speed and feed rate. There is no precise experimental method that can be used to check the analytical results. This paper presents a review of the analytical and experimental methods used to measure cutting temperature. Some experimental results using different methods are presented.

Glass has change the world more than any other material. This seminar deals with the glass processing and some different types of glasses and their applications. As we know that glass is transparent silica product which may be amorphous or crystalline depending upon the heat treatment. To manufacture it, a mixture of silica and other oxides are melted and then cooled to a rigid condition. Glass does not change from a liquid to a solid at a fixed temperature but remains in a vitreous noncrystalline state. In this seminar we will look at the main methods used for processing of glass products glass processing could be said to be the most important processing method for glass. We will also look at processes that are used to modify glasses for specific applications .Glass production starts with a mixture of raw materials which for glass manufacture often contain a high proportion of naturally occurring minerals.(e.g. sand and lime stone) to the final packaging. The major steps involve in the processing of glass are batch preparation, melting and refining, forming and shaping, thermal conditioning, annealing, finishing, cutting and inspection etc. Glass processing deals with the different stages of glass manufacturing such which type of raw materials are required for batch preparation then how melting takes place and also which type of forming process are carried out. After these whole process glass is drawn off for further cutting and inspection process after all these processes glass is obtained in required size and shape.

In the context of academic organizations, a technology transfer refers to the mechanism through which the institutions produce new technologies. Technology transfer may be accomplished in two ways: selling proprietary intellectual property to businesses or forming start-up firms. Universities, businesses, state and national economies and society as a whole prosper from successful technology transfer. Every institution, school, and university as a whole would benefit from the establishment of university industry links and a Technology Transfer Policy. It is critical to promote partnerships and strong collaboration between universities and industries that encourage realistic information development while also facilitating technology transfer. Students must be nurtured and equipped with realistic skills, which can only be accomplished by near collaboration and win-win agreements between universities and businesses in general. As a result, Ethiopia's educational system has placed a premium on university-industry linkages and technology transfer, resulting in the establishment of offices in all public universities throughout the region. The aim of this analysis is to evaluate the success of technology transfer and innovation in western Oromia, Ethiopia. To determine the root cause of the issue, quality tools: Cause effect diagram and Parato diagram was used in this analysis. Mitigation techniques were designed to prevent recurrence of known poor performance areas (weaknesses), as well as a planning structure that traces the area's goals.

Over the last two decades, the increased in industrialization, a lot of innovations, variety and volume leads to the improved standard of living associated with the number of advantages to the peoples due to the development of new manufacturing techniques. The industrialists are struggling a lot to increase the overall equipment Effectiveness (OEE) to reducing production time, unplanned stops due to equipment failures and material shortages, Quality Loss due to defective pieces etc,. Dimensional and quality changes are the most important troubles in production of PVC material using injection molding process. The aim of this study is to identify the root cause of the defected items and to generate a solution to reduce the percentage of defect by using quality control (QC) tools: Pareto Chart and Failure Mode and Effects Analysis (FMEA) are used for the continuous improvement and to reduce defects while manufacturing the PVS sole using injection molding process. Risk Priority Number (RPN) is obtained from past record, so as to hit upon the exact problem and the necessary measures are suggested for the future.

Meningkatnya permintaan produk dari konsumen membuat aktifitas
produksi padat, namun disisi lain ada beberapa permasalahan pada produktifitas yang belum terselesaikan membuat aktifitas produksi terhambat dan harus menambah jam kerja secara berkelanjutan. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh hardness material kuningan dan clearance pada progressive die terhadap kualitas produk kunci serta menentukan clearance yang optimal untuk proses produksi. Penelitian ini penulis menggunakan metode eksperimental suguhan untuk mengkaji sebab akibat dalam keadaan yang tidak memungkinkan,
dengan dilakukan pembagian menjadi dua bagian, yaitu kelompok treatment dan kelompok kontrol. Penelitian menggunakan variasi kekerasan material kuningansebagai kelompok treatment dan variasi clearance progressive die sebagai kelompok kontrol, material die menggunakan SKD11 yang sebelumnya dipanaskan agar memiliki kekerasan yang tinggi serta quenching dengan teknik modusi agar
memiliki kerapatan yang baik agar lebih mudah proses analisa pada die. Pengujian dilakukan menggunakan progressive die. Pengukuran ketinggian burr diukur dengan dial indicator. Hasil dari penelitian adalah semakin kecil clearance maka akan semakin besar burr yang dihasilkan, semakin besar clearance maka akan menghasilkan burr yang semakin besar, akan tetapi semakin kecil clearance dengan hardness material yang tinggi maka semakin kecil burr yang dihasilkan namun visual kurang baik untuk pemakaian jangka panjang, sedangkan semakin
lebar clearance dengan hardness material lembek maka semakin kecil burr yang dihasilkan, namun terlalu lebar clearance dengan hilangnya burr samping tetapi akan timbul potongan tidak sempurna pada tekstur potongan. Besarnya gaya yang dibutuhkan untuk memotong part adalah minimal 77,3 ton.

The process of cryogenic machining, due to increased demand for environmentally friendly manufacturing processes, has seen a growing interest in the machining community. This article presents an overview of cryogenic machining and its induced surface integrity characteristics such as surface roughness, topography, grain refinement and machining-induced layer, microhardness, phase transformation, residual stress and fatigue life in machining of various materials including difficult-to-machine materials, aerospace alloys, lightweight materials, etc. The effect of cryogenic machining on surface integrity characteristics is discussed, and compared with dry, Minimum Quantity Lubrication (MQL), and flood-cooled machining processes. In addition to being an environmentally friendly process, this study shows that cryogenic machining significantly contributes to improved functional performance of machined components through its superior and more desirable surface integrity characteristics.

In this paper, a wide literature review of soft computing methods in conventional machining processes of metal matrix composites is carried out. The tool wear, cutting force along with surface quality are presented in the different types of machining processes and examined thoroughly. Summary of the different particular soft computing approaches in machining such as turning, milling, drilling and grinding operations are thoroughly discussed. Furthermore, this work put emphases on the optimization and modeling of the machining process. The study will emphasis on the most general methods used by researchers in literature for developing the statistical and mathematical modeling using soft computing approaches including, genetic algorithm, response surface methodology, fuzzy logic, artificial neural network, Taguchi method and particle swarm optimization. In last section the comprehensive open issues and conclusion are presented for application of soft computing techniques in machining of metal matrix composite performance prediction and optimization.

Surface roughness prediction for the end-milling process, which is one of the major cutting processes, is a very important economical consideration in order to increase machine operation and decrease production cost in an automated manufacturing environment.
In this study; prediction of surface roughness (Ra) for Brass (60/40) material based on cutting parameters: cutting speed, feed rate, and depth of cut; was studied. 
Adaptive neuro-fuzzy inference system (ANFIS) was used to predict the surface roughness in the end milling process. Surface roughness was used as dependant variable while cutting speed of range (750 - 1750rpm), feed rate of range (50 - 250mm/min) and depth of cut of range (0.3 - 0.7mm) were used as predictor variables. Normal and feed forces were used as predictor variables to verify the ANFIS model. Different membership functions were adopted during the training process of ANFIS.
Surface roughness was measured in an off line manner using stylus based profile-meter (surtronic 3+). The normal and feed forces were measured in an on-line manner using two components dynamometer.
The effects of cutting parameters on the normal force, feed force and surface roughness were discussed.  Experimental test data were used to examine the ANFIS model by defining the reliability and percentage error of the model. Experimental results demonstrate the effectiveness of the proposed model. While the predicted surface roughness was compared with measured data; the mean square error has been found equal to 8.5 % hence the achieved accuracy is equal to 91.5 %.
Although this work focuses on prediction of surface roughness for end-milling operation, the concepts introduced are general; ie., prediction of surface roughness using ANFIS can be applied to many other cutting and machining processes.

Alat pemotong di industri permesinan yang bekerja dengan kecepatan tinggi sekitar 100000-150000 rpm dengan laju pengumpanan diatas 100 m/menit memerlukan spesifikasi khusus yaitu kekerasan>14,5 GPa; ketangguhan> 4 MPa.m1/2 untuk turning insert, > 8 MPa.m1/2 untuk bor, dan > 15 MPa.m1/2 untuk tap dan ketahanan aus yang baik pada temperatur kerja tinggi. Spesifikasi tersebut dipenuhi oleh bahan keramik yang memiliki titik leleh yang tinggi, kekerasan tinggi, stabilitas kimia yang baik, ketahanan oksidasi tinggi dan ketahanan korosi yang baik. Secara umum, alat pemotong keramik dikelompokkan menjadi tiga yaitu alat pemotong berbahan dasar alumina, silikon nitrida dan alat pemotong yang di-coating bahan keramik dengan ketebalan 4-15 μm. Secara komersial alat pemotong berbahan keramik sudah diaplikasikan pada industri permesinan di Indonesia namun kebutuhannya masih diperoleh secara impor karena belum ada produsen alat pemotong keramik dalam negeri. Oleh karena itu, pengembangan industri alat pemotong keramik di Indonesia mempunyai prospek yang baik. Pengembangan produk alat pemotong keramik termutakhir antara lain alat pemotong yang dilapisi oleh AlTiN yang memiliki ketahanan termal dan waktu pakai yang lebih baik dibandingkan dengan senyawa karbida, alat pemotong berbasis cermet yang mampu bekerja pada kecepatan pemotongan 300-500 m/menit dan alat pemotong keramik diperkuat dengan whisker yang difabrikasi secara in situ atau substitusi karbon.

Chip formation in metal cutting is inevitable and has a remarkable effect on tool state and therefore on the tool life. The work presented here introduces a new technique to independently monitor the chip formation effect on the tool state. This has been done by separating the chip formation events from the rest of the frequencies of occurrences. A customized tool holder and sensor setup are designed and integrated with the conventional tool holder to capture the signals from chip formation independently during turning. The signals taken by acoustic emission (AE) sensor represent the effect of chip formation on the tool state. The frequencies remaining below the transient offset signal are mostly coming from the tool wear and plastic deformation of the workmaterial. It has been observed that the acoustic emission is more susceptible to entire occurrences in turning. The time domain signal and corresponding frequency response can predict the tool state effectively. From raw AE signals and their RMS values, the tool wear and plastic deformation are observed to increase with the increase of cutting speed, feed rate and depth of cut. However, the tool wear has been found to decrease with chip breakage even at higher cutting speed and feed rate, and this has been verified by measuring the tool wear. The chip formation frequency has been found to vary between 68.3 kHz and 634.83 kHz while the maximum intensity was observed at 97.7 kHz.

In a modern and highly competitive manufacturing environment, manufacturing plays a virtual role in the industry to store both finished and unfinished goods. Now, industries are trying to adopt a high adoption and flexible warehouse design in order to minimize inventory costs. Designing a convenient warehouse plan is a critical process because it has a direct impact on the efficiency and productivity of your warehouse. The intended provision should organize processes in a logical order that can help streamline operations, increase productivity and reduce expenditures. This study looks at the design of a warehouse for a central pumping station. The station is currently processing an issue to store the product. The current layout and operations were reviewed and it was concluded that there are no effective warehouse techniques being adopted. The main aim to develop a warehouse plan for the facility to improve the flow of product and
reduces inefficiencies in daily operations. These suggestions aim to improve operational efficiency at a minimal cost of implementation

This study presents investigation of chip formation process of Ti-5553 alloy that is a next generation near beta titanium alloy and has potential to be replaced with commonly used Ti-6Al-4V due to its superior properties such as high corrosion and fatigue resistance. Experimental part of this study includes orthogonal cutting process of Ti-5553 alloy under dry, cryogenic, minimum quantity lubrication (MQL) and high pressure coolant (HPC) conditions. Various cutting speeds were taken into account to observe chip-tool contact length, forces, temperature, chip morphology resulting from various machining conditions. Experimental study demonstrates that HPC and cryogenic help to improve chip formation process of this alloy. By implementing Johnson–Cook model, orthogonal cutting process of this alloy in dry and cryogenic conditions is simulated utilizing Deform 2D commercial software. Predicted force, temperature, and chip morphology show good agreement with experimentally measured data.

It is well known that soft iron owes its transformation into steel to the addition of carbon. Carbon is the hardest substance on Earth - diamond. Carbon is the mainstay of Life on Earth, since everything living on our planet is built from it. This all means: carbon is the mainstay of our world. But find out: it is also the stronghold of the entire Universe! The mythical metal orichalcum spoken of by Plato and Tolkien's mithril are carbon, structurally superior to diamond. The Moon is made from it by the hand of God. The UFO is made from it by the hand of the Other. // Общеизвестно, что своим превращением в сталь мягкое железо обязано добавке углерода. Углеродом есть самое твердое вещество Земли — алмаз. Углерод — оплот Жизни на Земле, ибо из него на ней построено живое. Все это означает: углерод в нашем мире есть главная твердь. Но узнайте: он есть и твердь Мира! Мифичный металл орихалк, о каком рек Платон, и мифрил Толкина — это углерод, структурно высший над алмазом. Из него рукою Бога сделана Луна. Из него рукой Иного сделан НЛО.

The use of response surface methodology for minimizing the surface roughness in machining titanium alloy, a topic of current interest, has been discussed in this article. The surface roughness model has been developed in terms of cutting parameters such as cutting speed, feed, and depth of cut. Machining tests have been carried out using CVD (TiN-TiCN-Al2O3-TiN) coated carbide insert under different cutting conditions using Taguchi's orthogonal array. The experimental results have been investigated using analysis of variance (ANOVA). The results indicated that the feed rate is the main influencing factor on surface roughness. Surface roughness increased with increasing feed rate, but decreased with increasing cutting speed and depth of cut. The predicted results are fairly close to experimental values and hence, the developed models can be used for prediction satisfactorily.

https://www.tandfonline.com/doi/abs/10.1080/10426910701774700#.UdZ2pqyTX1U

Over the last two decades, the increased in industrialization, a lot of innovations, variety and volume leads to the improved standard of living associated with the number of advantages to the peoples due to the development of new manufacturing techniques. The industrialists are struggling a lot to increase the overall equipment Effectiveness (OEE) to reducing production time, unplanned stops due to equipment failures and material shortages, Quality Loss due to defective pieces etc,. Dimensional and quality changes are the most important troubles in production of PVC material using injection molding process. The aim of this study is to identify the root cause of the defected items and to generate a solution to reduce the percentage of defect by using quality control (QC) tools: Pareto Chart and Failure Mode and Effects Analysis (FMEA) are used for the continuous improvement and to reduce defects while manufacturing the PVS sole using injection molding process. Risk Priority Number (RPN) is obtained from past record, so as to hit upon the exact problem and the necessary measures are suggested for the future.

Many different families of plastics are used in industry. The demand for the machining of plastics has recently increased. In most cases, traditional metal machining techniques and tools are being used in the machining of plastics. The present paper reviews the conventional mechanical machining of plastics. The cutting phenomena as indicated by the types of chips formed under various cutting conditions, and the cutting forces for the single-edge cutting of two broad types of plastics are discussed. When drilling plastics, the type of chip produced, the torque, and the thrust are considered. A general idea about the milling of plastics is shown. The possibility of grinding thermosets and thermoplastics using an open grinding wheel is discussed with reference to bond type, grit type, grit size and porosity. © 1995.

https://ac.els-cdn.com/0924013695019170/1-s2.0-0924013695019170-main.pdf?_tid=606a5b84-1d34-11e4-8f16-00000aab0f02&acdnat=1407307332_4796687b1dc145cacb860419bb2e0266

A comprehensive study and FEM simulation of ball nose end milling on tool wear behavior and chip formation had been performed on Inconel 718 (nickle-based superalloy) under minimum quantity lubricant (MQL) condition. In this paper, the investigation was focusing on the comparison of up-milling and down-milling operations using a multi-layer TiAlN/AlCrN-coated carbide inserts. A various cutting parameters; depth of cut, feed rate and cutting speed were considered during the evaluation. The experimental results showed that down-milling operation has better results in terms of tool wear compared to up-milling operation. Chipping on cutting tool edge responsible to notch wear with prolong machining. It was observed that the chips formed in up-milling operation were segmented and continuous, meanwhile down-milling operation produced discontinuous type of chips.

The aim of this study is to determine the effect of the machining parameters and tool geometry. The turning operation is carried out as per the Design of Experiments (DoE) of Response Surface Methodology (RSM) to predict the temperature rise of aluminium-6061 as a cutting material and Al 2 O 3 coated carbide tool is used as a cutting tool for turning operation. The ANOVA analysis is used to measure the performance quality and mathematical model is developed. The values of probability >(F) is less than 0.05 indicates, the model conditions are significant. The cutting speed is the most influencing parameters compared to other parameters. For the optimum machining parameters leading to temperature rise, the Artificial Neural Network (ANN) model is trained and tested using MAT Lab software. The ANN recommends best minimum predicted value of temperature rise. The confirmatory analysis results, the predicted values were found to be in commendable agreement with the experimental values.

The goal of metal cutting research is to predict process conditions accurately with a model or a simulation, in order to optimize and develop the processes. Development of such a model requires understanding of multiple branches of physics and engineering such as continuum mechanics, thermodynamics, tribology and materials science. For an accurate model, each aspect of the process must be modelled properly, or at least the effects of a certain phenomenon must be shown to be negligible. This paper investigates the effect of the temperature dependence of material properties on metal cutting simulations for three different engineering materials: AISI 1045 steel, AISI 7075 aluminium and AISI 304 stainless steel. It is generally accepted that the flow stress of metals is dependent on the temperature, but modulus of elasticity, thermal expansion, heat capacity and thermal conductivity are often considered constants and their effect is considered negligible. In this study, orthogonal turning of the materials is simulated with constant material properties and material properties that are functions of temperature. Each material property combination is simulated to test their effect on the results to investigate the individual and interdependent effects. Based on the results, a general guideline can be formed regarding the importance of heat capacity, thermal conductivity, modulus of elasticity and heat transfer.

Abstrak Proses pembentukan dengan menggunakan mesin perkakas memiliki keragaman jenis mesin perkakas yang dapat digunakan, pemilihan mesin-mesin tersebut dilakukan berdasarkan bentuk, dimensi dan jenis bahan baku yang digunakan. Mesin milling merupakan salah satu mesin perkakas yang berfungsi untuk membentuk permukaan logam dengan menghilangkan sebagian benda kerja atau dikenal dengan geram (chip). Proses pemesinan dapat dilakukan melalui proses face milling dan side milling, tentunya bila produk yang dihasilkan seperti cetakan (mold), maka memerlukan nilai kekasaran yang kecil pada bagian permukaan dan sisinya, maka untuk mendapatkan nilai kehalusan permukaan yang baik tersebut, pemilihan jenis mata pahat terhadap benda kerja yang digunakan menentukan dalam pemilihan kombinasi parameter pemotongan. Berdasarkan hal tersebut, maka penelitian ini dilakukan untuk menganalisa pengaruh parameter pemotongan terhadap kekasaran permukaan logam baja pada proses side milling dan face milling. Penelitian ini bertujuan untuk mengetahui faktor-faktor yang mempengaruhi terhadap kekasaran permukaan yang dihasilkan dan mendapatkan kecepatan pemotongan yang sesuai untuk proses milling logam baja dengan menggunakan mata pahat karbida end milling. Penelitian ini dilakukan dengan metode eksperimen menggunakan mesin milling CNC, lima tingkat variasi kecepatan pemotongan digunakan dalam proses pemesinan, dan setiap satu kali proses pemesinan selesai dilaksanakan, maka kekasaran permukaan benda kerja di ukur menggunakan alat ukur surface test " mitutoyo ". Dari penelitian yang dilakukan dapat diketahui bahwa kecepatan pemotongan memberi pengaruh terhadap perubahan nilai kekasaran permukaan benda kerja logam, semakin tinggi kecepatan potong yang digunakan maka nilai kekasaran permukaan yang dihasilkan semakin kecil artinya permukaan benda kerja menjadi semakin halus. Secara berurutan kecepatan pemotongan yang digunakan pada proses side milling yakni 80 m/min, 90 m/min, 100 m/min, 110 m/min, 120 m/min menghasilkan nilai kekasaran permukaan yaitu 4,39 μm, 4,10 μm, 4,09 μm, 3,60 μm dan 3,26 μm. Dan pada proses pemesinan face milling nilai kekasaran permukaan adalah 4,10 μm, 4,05 μm, 4,01 μm, 3,91 μm dan 3,81 μm. Kata kunci: Proses side milling, face milling, parameter pemotongan, kekasaran permukaan. 1.PENDAHULUAN Pemesinan logam merupakan salah satu proses pembentukan logam yang umum digunakan dalam industry manufaktur. Proses pemotongan logam merupakan suatu proses yang digunakan untuk merubah bentuk logam sehingga menjadi bentuk yang diinginkan. Proses permesinan logam tidak dapat dipisahkan terhadap penggunaan mata pahat potong. Sifat-sifat dan geometri mata pahat potong memberi spesifikasi tersendiri dalam pemilihan parameter pemotongan yang hendak digunakan. Sedangkan parameter pemotongan memberikan spesifikasi tersendiri pada proses pemesinan yang akan memberi efek terhadap perubahan kondisi permukaan benda kerja, umur pahat, waktu pemesinan, gaya dan daya pemotongan. Dari dahulu hingga kini, teknologi pembentukan logam mengalami perkembangan yang pesat. Dalam dunia manufaktur khususnya industry pemotongan logam juga mengalami perkembangan yang sangat pesat, baik itu mesin-mesin, metode dan system maupun mekanisme pemotongan yang digunakan. Seperti pada mesin perkakas konvensional yang penggunaan mesin ini mengalami perkembangan menjadi mesin dikontrol secara otomatis yang dikendalikan oleh komputer, sehingga ini banyak

Non-linear regression analysis techniques are used to establish models for wear and tool life determination in terms of the variation of a ratio of force components acting at the tool tip. The ratio of the thrust component of force to the power, or vertical, force component has been used to develop models for (i) its initial value as a function of feed, (ii) wear, and (iii) tool lifetimes. Predictions of the latter model have been compared with the results of experiments, and with predictions of an extended Taylor model. In all cases, good predictive capability of the model has been demonstrated. It is argued that the models are suitable for use in adaptive control strategies for centre lathe turning. #

В статье рассмотрены различные технологические схемы процессов гибридной сварки и резки металлов и сплавов. Показано, что применение технологической схемы лазерно-плазменной резки и сварки с коаксиальным подведением обоих источников энергии с одной стороны обрабатываемой детали приводит к появлению так называемого гибридного эффекта, который заключается в «привязке» анодного пятна дуги к зоне действия излучения, стабилизации ее горения в гибридном процессе при токах до 300 А и снижении напряжения на дуговом промежутке из-за повышения его электропроводности за счет перегрева плазмы лазерным излучением, что позволяет значительно увеличить скорости процессов резки и сварки без повышения погонной энергии. Применение технологических схем лазерно-плазменной резки и сварки с наклонным расположением обоих составляющих гибридного процесса, подводимых с одной стороны обрабатываемой детали, также приводит к появлению гибридного эффекта, но при этом он может быть менее явно выраженным, а также возникает опасность повреждения деталей оборудования (например, оптических элементов) отраженным от рабочей зоны излучением.

Nickel-base superalloy Inconel 718 is a high-strength, thermal-resistant. Because of its excellent mechanical properties, it plays an important part in recent years in aerospace, petroleum and nuclear energy industries. Due to the extreme toughness and work hardening characteristic of the alloy, the problem of machining Inconel 718 is one of ever-increasing magnitude. This investigation optimized the machining characteristics of Inconel 718 bars using tungsten carbide and cermet cutting tools. The approach is based on Taguchi method, the signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) are employed to study the performance characteristics in turning operations. The roundness and flank wear of the ultrasonically and conventionally machined workpieces were measured and compared.

Steady-state turning experiments were carried out with multilayer coated inserts consisting of TiN/Al 2 O 3 /TiCN deposited on a carbide substrate. Confocal microscopy was used for the first time to observe the topography of crater wear evolution in multilayer coated inserts. A hump made of TiN coating next to a growing crater of Al 2 O 3 , traces of attached steel, and the maximum depth regions have been identified. Scoring marks were also detected in the TiN layer, indicating the presence of abrasion wear. Interestingly, the crater depth was stagnant once it reached the Al 2 O 3 layer, and the wear progresses by broadening the area of exposed Al 2 O 3 . It was concluded that the effectiveness of multilayer coated tools comes from the dissolution resistance of the Al 2 O 3 layer, which delays depth growth and develops the wear front into a wider area. Confocal microsocopy was found to be a valuable tool to obtain wear topography for multilayer coated tools.

Wiper inserts have the characteristics of eliminating many grinding operations and achieving an excellent surface. They also improve component quality and roundness compared with grinding. This paper exposes a performance comparative analysis, involving the criteria of surface roughness (R a , R t and R z ) during high strength steel's turning operation, between the conventional and wiper inserts. The main parameters considered in this study are; the speed of cutting (CS), the feed rate (FR), and the cutting depth (DOC). The test plan was carried-out through (128) test specimens divided into two equal sample groups (A and B), each consists of (64) test specimens. Specimens of group (A) and (B) are tested using wiper and conventional inserts respectively. To apply the required testing conditions, a CNC Turning machine equipped with Sinumeric 840-D, was used. The surface roughness was evaluated using a surface roughness tester (Tesa-rugosurf 90-G). The most important parameters affecting the surface roughness are highlighted. Statistical tests used for this study including the analysis of variance (ANOVA) and the response surface methodology (RSM) are presented. The results show the significance of cutting depth and feed rate in the reduction of surface roughness. The machining conditions producing the optimum roughness of the surface, in the experiment range, were investigated using desirability-function-approach for the optimization of multiple-factors of response. The results showed that the quality of surface derived with the wiper carbide insert has significant improvement in comparison to the conventional carbide insert. The maximum improvement of 3.5 times between the wiper insert and conventional insert was achieved at a surfacing speed of 75 meter/min and is limited to 3, 2.5 and 2 times for a surfacing speed of 100, 125 and 150 meter/min, respectively.

Konvansiyonel olarak metal sac kesim için en çok kullanılan sistemler lazer sistemleridir. Bunun en önemli nedeni, özellikle fiber lazer sistemleri için konuşmak gerekirse, kompakt yapıda olması, bakım gerektirmemesi, düşük elektrik tüketimi, yüksek verimlilik, geniş bir skalada işlem yapabilmesi, basit kullanımı gibi sıralanabilir. Mesela diğer kesim sistemleri farklı metalleri kesmek için farklı bıçaklar ya da farklı nozzle tipleri kullanmaları gerekirken lazer için böyle bir durum söz konusu değildir. Lazer sistemlerindeki tek handikap eğer işlenecek olan malzeme kullanılan lazerin dalgaboyunu yüksek derecede yansıtır özelliğe sahipse bu durumda işlem yavaşlayabilir.
Lazer ile metal sac kesimin fiziğine değinmek gerekirse, cihazdan elde edilen lazer ışını işlem yapılacak olan metalin üzerinde çok küçük bir noktaya odaklanarak (bir kaç mikrondan bir kaç yüz mikrona kadar değişebilir) bu bölgeye çok yüksek miktarda enerji aktarımı sağlanır. Bu yüksek enerji sayesinde odaklanmış olan bölge hızla ısınarak bölgedeki malzeme direkt olarak buharlaşmaya başlayıp bölgeden uzaklaşır. Bu işlemin tekrarlanması ile kesim işlemi yapılmış olur. İşlem sırasında çeşitli inert gazların kullanılması hem işlemi hızlandıracak hem de çapaksız bir işlem yapılmasına olanak sağlayacaktır.