Machining

Cutting tool wear is a production management problem for manufacturing industries. It occurs along the cutting edge and on adjacent surfaces. This article describes steady-state wear mechanisms, tertiary wear mechanisms, and tool replacement. It provides information on tool failure and its consequences. The article details the modeling of tool wear by using the Taylor's tool life equation. The article concludes with information on the requirements of a successful tool life testing program: the test plan objective, designing the test, conducting the test, analyzing the results, and applying the results.

The present study focuses on optimizing the process parameters during machining of NiTi (Nickel-Titanium) shape memory alloy by wire electric discharge machining (Wire EDM) for simultaneously maximizing material removal rate and minimizing tool wear rate u sing brass wire as electrode. Taguchi's design with utility and modified utility optimization techniques have been used for simultaneous multi-response optimization. Different analyses were performed to determine the optimal settings in both utility and mo dified utility concepts. The optimal results of both methods disclose that the pulse on time of 115µsec and pulse off time of 40µsec with spark gap set voltage of 20V are useful for maximizing material removal rate and minimizing tool wear rate. The optimization results indicate that the spark gap set voltage is the majority significant parameter that affects the tool wear rate and material removal rate.

Laser Assisted Machining (LAM) is a new and innovative way to machining hard-to-wear materials, which are difficult to machine using conventional cutting methods. Laser assisted machining combines laser technology with traditional machining methods. Laser assisted turning is hybrid process which combines laser heating and conventional turning. Laser assisted machining could be implemented at the plant giving cost savings. This paper presents the information and the methodology of laser assisted turning. How to cite this article: Radovanovic, M. and Dašić, P.: Laser assisted turning. In: Proceedings of the 6th International Conference "Research and Development in Mechanical Industy" (RaDMI-2006), Budva, Montenegro, 13-17 September 2006. Kraljevo: Faculty of Mechanical Engineering and Trstenik: High Technical Mechanical School, 2006, pp. 312-316. ISBN 978-86-83803-21-7.

An optimum experimental design to determine the coefficients of the Extended Taylor's Equation in machining is proposed. The technique is based on the minimisation of the ratio between maximum and minimum singular values of the matrix of sensitivity of the tool life related to the machining parameter variations. This procedure generates the best set of cutting conditions to be used in tool life tests which results in a fast convergence of the coefficients and their confidence intervals. This technique was compared to the commonly used fractional factorial design when face milling AISI 1045 steel with cemented carbide cutting tools. The results showed a considerable reduction in the number of tests required to obtain a reliable equation when the optimum experimental procedure was used when compared to the factorial design.

Recently all environmental worries are calling for reducing the usage of fluids in machining operations. One of the promising solutions that appeared lately is minimum quantity lubrication (MQL). This research aimed to develop an eco-friendly cooling system for a lathe machine and assess its performance. After considering the customer needs, the needs were translated into engineering specifications in the conceptual design phase, and then the quality function deployment was developed. Three concepts were generated and evaluated considering the selection criteria, and a final concept was selected using the decision matrix method. Following this, a detailed design and fabrication of the subsystems such as the oil tank and a structure accommodate all the components. The developed system was tested on six different workpiece samples to compare the MQL system with the conventional one. In general, the MQL system resulted in lower surface roughness values as well as lower tool wear.

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.

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

Chip morphology plays a crucial role in determining the tool life and structural integrity of a part. The main aim of this paper was to generate predictive models for chip morphology parameters such as chip length, chip width, chip thickness and shear band utilizing MINITAB 17 Statistical Software. The models were proven to be valid except for that of chip thickness whose average percentage error fell outside 5.0. The optimal cutting conditions for the chip morphology parameters were also determined.

In this study, a review of the available literature on lubrication techniques during machining processes was conducted. Factors such as workpiece material, tool material and machining conditions were observed to be vital to the performance of any of the techniques. The performance and drawback of each technique were highlighted based on the machining conditions. It concludes by making a case forminimum quantity lubrication (MQL) method using vegetable oil-based lubricant in different machining processes, as a way of addressing the environmental health issues and cost associated with the application of lubricant in machining processes. © 2012 Elsevier Ltd. All rights reserved.

http://ac.els-cdn.com/S0959652612005483/1-s2.0-S0959652612005483-main.pdf?_tid=286d8dc8-1d34-11e4-bb4c-00000aab0f01&acdnat=1407307238_0c3e33d1e8b0310f15a8747dee0a8c5f 
http://www.sciencedirect.com/science/article/pii/S0959652612005483

Tháp giải nhiệt Tashin TSS & TSC được sản xuất hoàn toàn từ những chất liệu cao cấp không bị ăn mòn, độ bền cao, khả năng dẫn nhiệt tốt nên sử dụng tháp giả nhiệt Tashin TSS & TSC cho hiệu quả làm việc bền bỉ trong nhiều năm.
Điện máy Hoàng Liên hiện đang là đại lý phân phối chính hãng tháp nước giải nhiệt Tashin tại Hà Nội, TP.HCM và các tỉnh thành trên cả nước.
Truy cập: https://dienmayhoanglien.vn/thap-giai-nhiet-tss.html

The surface integrity of the machined parts reveals the performance of the machining process carried out on it. Hard turning is the most common and popular finishing operation that relies on surface roughness, cutting force. In this experimental work, the machining process is done in CNC machine by using the ceramic cutting tool. The primary cutting parameters namely cutting velocity, feed and Depth of cut are selected for machining of martensitic stainless steel 416. The optimal range of cutting parameters are selected for martensitic stainless steel 416 before the experimental machining process is carried out to ensure the less effort in achieving optimal parametric combinations. By adjusting the range of cutting parameter, the machining characteristics (Surface roughness, cutting force) are measured. After the optimization of machining characteristics, are carried out using renowned Taguchi method with the help of Mini Tab software. Taguchi approach is quite simple and efficient to obtain the optimal set of the machining parameters. Finally confirmation tests were carried out for the optimal machining parameters to ensure the reliability of the experimental results obtained previously. The confirmation results were found to be good and fit.

Materials are playing vital role in recent past, in-situ Al-Tic with 5% TiC composite
was produced by the reaction with the halide salt K2TiF6. SEM and EDX tests were
performed on the prepared Al-TiC test specimen. As the micro hardness test was performed
for the test loads of 100 grams and 300 grams. By the addition of TiC the hardness of the
material was increased. There was a small variation in hardness value for 100 grams and 300
grams test load conditions.

In the machining of metal cutting, cutting tools are the main things that must be considered. Using improper cutting parameters can cause damage to the cutting tool. The damage is Built-Up Edge (BUE). The situation is undesirable in the metal cutting process because it can interfere with machining, and the surface roughness value of the workpiece becomes higher. This study aimed to determine the effect of cutting speed on BUE that occurred and the cutting strength caused. Five cutting speed variants are used. Observation of the BUE process is done visually, whereas to determine the size of BUE using a digital microscope. If a cutting tool occurs BUE, then the cutting process is stopped, and measurements are made. This study uses variations in cutting speed consisting of cutting speed 141, 142, 148, 157, 163, and 169 m/min, and depth of cut 0.4 mm. From the results of the study were obtained that the biggest feeding force is at cutting speed 141 m/min at 347 N, and the largest cuttin...

— Surface roughness in drilling process is important aspect so there is needs to minimize surface roughness while drilling. This paper investigates the influence of drilling parameters such as spindle speed, feed rate and cutting tools on surface roughness while drilling titanium alloy. The experiments have been conducted by employing L27 orthogonal array by considering HSS, Coated HSS and carbide drills. After experimentation second order empirical modelling was done using regression method. Finally, optimization of drilling parameters for surface roughness was done through genetic algorithms. The genetic algorithms give minimum value of surface roughness was 0.0689 corresponding optimize drilling parameters were 576.069, 0.03, and carbide as spindle speed, feed rate and cutting tool respectively.

Ti and Ti-based alloys have unique properties such as high strength, low density and excellent corrosion resistance. These properties are essential for the manufacture of lightweight and high strength components for biomedical applications. In this paper, Ti properties such as metallurgy, mechanical properties, surface modification, corrosion resistance, biocompatibility and osseointegration in biomedical applications have been discussed. This paper also analyses the advantages and disadvantages of various Ti manufacturing processes for biomedical applications such as casting, powder metallurgy, cold and hot working, machining, laser engineering net shaping (LEN), superplastic forming, forging and ring rolling. The contributions of this research are twofold, firstly scrutinizing the behaviour of Ti and Ti-based alloys in-vivo and in-vitro experiments in biomedical applications to determine the factors leading to failure, and secondly strategies to achieve desired properties essential to improving the quality of patient outcomes after receiving surgical implants. Future research will be directed toward manufacturing of Ti for medical applications by improving the production process, for example using optimal design approaches in additive manufacturing and investigating alloys containing other materials in order to obtain better medical and mechanical characteristics.

In order to carry out a machining process with high efficiency, a study was performed that relates cutting conditions with the consumption of electric energy in a CNC machining center. During the experiment, the influence of the axial depth of cut and radial depth of cut on the energy consumption was evaluated. These parameters directly influence the machining cross section and the forces involved in the process. Severe cutting conditions increase the material removal rate (MRR), but they increase the forces and require more energy consumption for cutting. Slighter conditions require less effort to perform cutting, but machining times are increased. AISI P20 steel was machined by milling in a machining center and the relationship between material removal rate and electric power consumption was evaluated.

The effects of cutting conditions on the cutting force in the longitudinal turning of C60E steel were experimentally investigated. During experiments, three components of cutting force were measured, the main cutting force, the feed force and the passive force. The width of cut, the thickness of cut, feed, depth of cut and tool cutting-edge angle are found to be affecting force components. The cutting force is influenced not only by cutting conditions but also the cutting edge geometry and the material of workpiece. The influence of the cutting edge geometry and the material of workpiece is not investigate.

How to cite this article:
Radovanović, M.; Dašić, P. and Janković, P.: Experimental determination of cutting force by longitudinal turning of C60E steel. Modelling and Optimization in the Machines Building Fields (MOCM), Vol. 12, No. 2 (June 2006), pp. 113-119. ISSN 1224-7480.

The paper presents an update of the recent literature on advances in machining of difficult to machine materials such as nickel and titanium-based alloys, and composites used in aeroengine and aerostructure applications. The review covers the following issues: advances in high-performance cooling techniques as cryogenic machining, minimum quantity lubrication, the combination of MQL and cryogenic cooling, and high-pressure lubricoolant supply and hybrid cutting processes-vibration assisted machining (both low and high frequency), laser, plasma and EDM assisted machining. Examples of applications in industrial processes are also given.

In this paper, a study based on the finite difference method is presented to anticipate tool and chip temperature fields in continuous as well as interrupted machining. Continuous machining operations like orthogonal cutting are considered for study the heat transfer between the tool and chip at the tool rake face contact surface. For temperature variation, primary heat zone is considered where number of parameter come into analysis i.e. shear energy created in primary zone, friction energy produced at chip tool interface. Later, model is extended to milling where cutting is interrupted. it is discovered that increasingly steady expectations of rake face temperatures can be made. From this work data has been gotten on the state of the zones of plastic distortion in metal cutting and on the appropriation of heat age inside these zones

The stop-motion armatures in contemporary times have apparently new and specific solutions to demands of the characters that they allow animate efficiently, but we can trace its heritage to an historically specific project: a 1:8 scaled version of the starring Gorilla from Mighty Joe Young, 1949, designed by Ray Harryhausen under the supervision of Wilis O'Brien and manufactured by Harry Cunningham between 1947 and 1949 who earned the nickname " Jennifer " by Harryhausen, one of their animators together with Pete Peterson. Skeletons of stop-motion for feature films are internal structures to the figures of characters who often have compound metal joints-articulations with more than one mechanic component to provide controllable friction by pressure adjustment. The compound metallic joints allow both accurate angular variation (drive function, muscular system) and adequate support of the structure and coverage (structural function, skeletal system). New characters require new solutions but do not derive as much of anthropomorphic aspect invariably referring to developments present in Jennifer. The variation in body elements is that they have brought a solution or another in articulation strategy, where equating three features: support capability, the positional variability, ​and volume of all parts of the joint. It is the influence of the culture of illustration in stop-motion starting from Tim Burton and Henry Selick who radicalize the formal variations of the characters, making them mechanical challenges that Jennifer paradigms still manage to answer. In extreme cases happens the use of external support mechanisms, now easier to hide by digital imagery manipulation. Published in AVANCA | CINEMA 2015. http://www.avanca.org/

The growth of machining science has evolved over the years; its integrity is dependent on the aesthetics and material properties of finished products. The global trend of machining operations has been dependent on energy intensity and cost. This energy has also been linked with the surface roughness and integrity of the finished part. In developing countries like Nigeria where CNC machining is gradually finding its way into the manufacturing sector, it is appropriate at this time to evaluate the impact of surface roughness and surface integrity on machine component from CNC and conventional lathe. This research therefore aimed at investigating the surface roughness obtained during a Teflon turning operation on the CNC and the conventional machine tool. In this study arithmetical mean roughness value (Ra) was measured and recorded for both CNC machined part and conventional lathe at three different orientation and seven points on each orientation. It can be concluded that the surface roughness obtained at different orientation when turning Teflon on the CNC is smoother than that obtained with the conventional machine tool as the arithmetical mean roughness value (Ra) measured from all points at different orientation lower in CNC than conventional Lathe.

The paper presents an update of the recent literature on advances in machining of difficult to machine materials such as nickel and titanium-based alloys, and composites used in aeroengine and aerostructure applications. The review covers the following issues: advances in high-performance cooling techniques as cryogenic machining, minimum quantity lubrication, the combination of MQL and cryogenic cooling, and high-pressure lubricoolant supply and hybrid cutting processes-vibration assisted machining (both low and high frequency), laser, plasma and EDM assisted machining. Examples of applications in industrial processes are also given.

PT. Kubota Indonesia adalah salah satu perusahaan yang melakukan produksi mesin diesel di Indonesia. Dalam proses produksi mesin diesel Kubota, masing-masing komponen mesin yang akan dirakit harus melalui proses pemesinan terlebih dahulu. Salah satu komponen yang telah dilakukan proses pemesinan secara mandiri di PT. Kubota Indonesia yaitu crankshaft.
Kontrol 2 posisi atau on-off adalah salah satu metode kontrol konvensional yang banyak digunakan di dunia industri. Salah satu aplikasi dari kontrol on-off adalah pada mesin gripper. Untuk meningkatkan keselamatan kerja di perusahaan maka operator memakai mesin gripper untuk meletakkan dan mengambil crankshaft dari mesin yang digunakan untuk proses machining yaitu mesin crankshaft lathe. Mesin gripper ini menggunakan PLC sebagai pengendalinya.
Dalam laporan kerja praktek ini, penulis akan membahas mengenai gripper yang digunakan pada mesin crankshaft lathe, komponen-komponen pembangun dari mesin tersebut seperti PLC, aktuator, sensor, efektor serta langkah kerja mesin gripper tersebut dan pemrogramannya ke dalam PLC.

... cle fracture/debonding force at lower feed (as will be seen in Section 5.3.1) also indicates higher tool–particle interactions. These will cause greater surface dam-age at low feed. In the case of non-reinforced alloy no such damage is expected at low feeds, which accounts for its ...

This paper describes a review of basic terms and visualizations of the major components of the cutting tool geometry in orthogonal turning process. The parameters like rake angle, depth of cut, feed rate, temperature and cutting speed are taken in to account so as to predict their effects on tool life. Their influences on cutting forces and tool geometry have also been referred.

Ultrasonically assisted drilling (UAD) is a novel machining technique suitable for drilling in hard-to-machine quasi-brittle materials such as carbon fibre reinforced polymer composites (CFRP). UAD has been shown to possess several advantages compared to conventional drilling (CD), including reduced thrust forces, diminished burr formation at drill exit and an overall improvement in roundness and surface finish of the drilled hole. Recently, our in-house experiments of UAD in CFRP composites demonstrated remarkable reductions in thrust-force and torque measurements (average force reductions in excess of 80%) when compared to CD with the same machining parameters. In this study, a 3D finite-element model of drilling in CFRP is developed. In order to model acoustic (ultrasonic) softening effects, a phenomenological model, which accounts for ultrasonically induced plastic strain, was implemented in ABAQUS/Explicit. The model also accounts for dynamic frictional effects, which also contribute to the overall improved machining characteristics in UAD. The model is validated with experimental findings, where an excellent correlation between the reduced thrust force and torque magnitude was achieved.

In this increasingly technological world, mining it’s the first step for any sketch and plays an important role in extraction and selective recovery to comply with the incessant demand of material that we need nowadays.

One of the most coveted materials it’s gold, necessary to wear as much for jewel like for
numerous application in the engineering world, since its use in aviation engines until applications of dentistry, among countless examples. But, how is supported this incessant hunger of gold?

This answer, some years ago, was to use a big quantity of workforce, which by means of hand tools they were able to get little amount of gold. Was a work tedious, not much remunerate and very dangerous.

In the middle of the XIX century, when they were discovered big rich zones in gold in Alaska and the northern zone of United States and Canada, they was knew like “gold rush” that’s did break up a little boom at the technological area beginning in this way a great number of surveys and digging of alluvial mining. Better machinery was available to be controlled by a small number of operators, obtaining large amounts of gold from the ground.

This inclination is continued until nowadays, that we have any type of high capacity mining machinery to obtain a high quantity of gold that’s present on the deck.

A type of machinery is known like “Trommel” o rotary screen, this machine is based on movement and pressure of water to release gold who it’s glued on the rock’s surface.

About this machine it is base the next project, we need a low spin speed, but enough for doing a progressive cleaning of rocks at the same time a high quantity of torque, for win all inertias and move with fluently rock- drum set.

So, for this, it is imperative to use a reducing mechanism able to harness the power of the engine and offer all requirements that we need, always taking into account security and protection of the environment.

The modern tiltrotor is an aircraft capable of efficient hover as well as high-speed forward flight. The large, flexible rotors needed for good hover performance are susceptible to an aeroelastic phenomenon known as whirl flutter in high-speed flight: high rotor inflow and the flexible nature of the rotors will result in negative aerodynamic damping when the tiltrotor is in airplane mode,
causing the coupled wing/rotor/pylon system to become unstable.

Traditionally, the tiltrotor whirl flutter margin has been increased through the use of thick wings of low aspect ratio, which
maximize the stiffness of the wings at the expense of increased structural weight and reduced aerodynamic efficiency. To increase the top speed of tiltrotors, new methods of analyzing and
mitigating the whirl flutter phenomenon must be developed.

This study focuses on the design and development of a semispan wind tunnel model that permits the testing of whirl flutter stability in a controlled, low-risk environment. The wind tunnel model was dynamically tested in the Penn State Hammond Low-Speed Wind Tunnel.

Five configurations were tested for modal damping variations with respect to tunnel speed. Two of these configurations ("Gen-2") were modified versions of the first-generation ("Gen-1") wind tunnel model designed and tested by S. C. Johnson in the 2012-2013 timeframe. Three configurations of an all-new model ("Gen-3") were developed to increase the realism of the test
specimen, and included features such as tuned wing modal frequencies, higher-Lock number rotor blades, and blade twist. Most importantly, the Gen-3 models were designed to flutter without the use of an added mass or unconventional center of gravity placement.

Gen-3 was developed through the use of an in-house computer code, which generated damping predictions for the wing modes at various tunnel speeds. Model components and support equipment were fabricated in-house by the author, with some components (e.g. those requiring computer-controlled machining) outsourced to local manufacturers. Wind tunnel tests were performed in the Hammond tunnel from October 2014 through January 2015; these tests showed that the experimentally-measured flutter speeds of the Gen-3 models were within 5-7% of the predicted values, with the Gen-3a (untwisted composite blades) fluttering at approximately 101 ft./sec., and the Gen-3b model (twisted composite blades) fluttering at approximately 97 ft./sec.

The present work has further validated the feasibility of whirl
utter testing at a small scale. The Gen-3 model was able to exhibit whirl flutter without the use of an additional mass, and will permit the testing of devices designed to enhance the whirl flutter margin within the current facility. The techniques used to fabricate the Gen-3 model show potential for introducing features such as blade
flexibility and an modular wing root flexure for a wider test regime.

Abrasive waterjet machining (AWJM) is a new machining process, the advantages of which include low cutting temperatures, no heat damage to the material being cut, minimal dust, and low cutting forces. This paper presents a state of the art review of research in this new process. The main topics discussed are mechanics of material removal, productivity, cutting forces, surface quality and nozzle wear.

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.