Verified email at gmail.com
School of Mechanical Engineering
Federal University of Uberlândia
B.Sc. in Mechanical Engineering (1987), and Ph.D. in Mechanical Engineering (1999), all of them in the Federal University of Uberlândia. Developed work as a Research Fellow (sabbatical): first time at Pontifical Catholic University of Minas Gerais (Belo Horizonte, MG, Brazil), from 1999 to 2000, second time at London South Bank University (London, UK) from 2004 to 2005 and third time at University of Kentucky (Lexington, USA) from 2014 to 2015. Has experience in Mechanical Engineering, acting on the following subjects: manufacturing of biomaterials, tribology, incremental sheet forming and sustainability. Nowadays is serving at Federal University of Uberlândia, Brazil.
Ph.D. in Mechanical Engineering.
M.Sc. in Mechanical Engineering.
B.Sc. in Mechanical Engineering.
Biomaterials, manufacturing, orthoses, and prostheses, monitoring, modeling.
Google Scholar Citations
Google Scholar h-index
Google Scholar i10-index
Wisley F. Sales, Julius Schoop, Leonardo R.R. da Silva, Álisson R. Machado, and I.S. Jawahir
Journal of Manufacturing Processes, ISSN: 15266125, Pages: 136-162, Published: October 2020 Elsevier BV
Antonio Favero Filho, Leonardo Rosa Ribeiro da Silva, Rodrigo de Souza Ruzzi, Eder Silva Costa, Wisley Falco Sales, Mark James Jackson and Álisson Rocha Machado
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Volume: 105, Issue: 1-4, Pages: 1343-1355, Published: 1 November 2019 Springer London
The nickel-based alloys have a growing demand in many fields due to their outstanding properties at high temperatures. These properties lead to relatively low machinability, one of the main obstacles to its more extensive use. Improvements in cutting tool quality are one of the key points to overcome the challenges. The decrease to a submicron scale of the grains of cemented carbide tools is one of the alternatives to improve the machinability of the nickel-based superalloys. In this paper, two different grades of submicron grains of uncoated cemented carbide tools, TMG30 (10% Co, S30-40) and CTS18D (9% Co, S20-40), were evaluated in the end milling process of Inconel 718, through a 24 factorial design of experiments having as parameters the cutting speed, feed rate, machining direction (up and down milling), and tool grade. The tool life, machining power, and surface roughness were used as machinability evaluators. It was found that the machining direction, cutting speed, and feed rate had a significant influence on the machinability output variables, with the machining direction being the most significant one. The differences in the two tool grades were too small to be statistically significant. Simulations using the finite element method of the effective plastic strain, validated by the measurement of experimental machining power, showed that the up milling presented around 14% more plastic deformation than the down milling, which combined with the work-hardenability of the Inconel 718 explains the shorter tool life of this condition.
Miguel Mandú Bonfá, Éder Silva Costa, Wisley Falco Sales, Fred Lacerda Amorim, Luis Henrique Andrade Maia and Álisson Rocha Machado
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Volume: 103, Issue: 1-4, Pages: 971-984, Published: 19 July 2019 Springer London
The main objective of this work is to evaluate the tool life and the workpiece surface roughness when applying a vegetable-based cutting fluid by minimum quantity of lubricant (MQL) at three different directions (main tool flank face, secondary tool flank face, and overhead) in turning AISI D6 hardened steel with polycrystalline cubic boron nitride (PCBN) tools with Al2O3 ceramic binder and TiN coating. Dry cutting was also tested for comparisons. Tool wear analyses were performed on the tools at the end of their lives within a scanning electron microscope (SEM). The application of the cutting fluid by MQL technique in the direction between the main tool flank face and the workpiece showed better results than the dry condition. The application of MQL through other directions (overhead and between the secondary tool flank face and the workpiece) also showed competitive results. Abrasion and adhesion were the prevailing mechanisms for the wear of the tools.
da Silva, Ruzzi, Teles, Sales, Guesser and Machado ISSN: 00431648, Volume: 426-427, Pages: 1646-1657, Published: 30 April 2019 Elsevier Ltd
Abstract The coefficient of friction at the workpiece-tool interface is one of the main influencing parameters in machining. It can be tribologically investigated using conventional and open tribometers, however, there is no consensus as to which type of test has the best correlation with the real machining process. This work aims at investigating the use of three different methods to measure the coefficient of friction in the machining of three types of high strength compacted graphite cast irons, with variations in the size of the free graphite phase and the presence or absence of molybdenum carbides in the matrix. The coefficient of friction of the process was measured using two progressive load conventional tribological tests, the progressive load single sliding test with load ranging from 0.5 to 40 N and the progressive load reciprocate sliding test in both dry and starved lubrication regimen, with load ranging from 48 to 83 N. The coefficient of friction was also measured in a conventional machining center used as an open tribometer, where ramp milling tests were performed in workpieces fixed on a piezoelectric dynamometer, with a cutting depth varying from 100 µm to 0, to simulate a regressive load. The following machining parameters were varied: cutting speed, feed rate, tool geometry, tool coating and the use of minimum quantity of lubrication in contrast to dry machining. As the main results, the predominance of lubrication, even in small quantities, was observed as the most influential parameter in the coefficient of friction. An inverse relationship was also observed between the hardness of the materials and the coefficient of friction independent of the lubrication condition used. The results of the coefficient of friction obtained in progressive load reciprocate sliding and open tribometer tests showed the best correlation with those found in the literature for this kind of materials.
Armando Marques, Mauro Paipa Suarez, Wisley Falco Sales, and Álisson Rocha Machado
Journal of Materials Processing Technology, ISSN: 09240136, Volume: 266, Pages: 530-543, Published: April 2019 Elsevier BV
Abstract The rule of thumb in the machining of nickel base superalloys with ceramic tools is to cut dry and no attempt of applying MQL with the addition of solid lubricant was made, according to the literature consulted. The main objective of this study is to evaluate the effect of the addition of solid lubricant in vegetal base oil applied by MQL (Minimum Quantity of Lubricant), when turning Inconel 718, with whisker-reinforced ceramic cutting tools (Al2O3 + SiCw). Tool life, tool wear mechanisms, surface integrity (microhardness, microstructure and roughness) and cutting force were evaluated. The results showed that the addition of MoS2 substantially improved tool life; types of dominant wear were the notch, flank and small crater, while the main wear mechanisms observed were adhesion and abrasion; cutting fluids improved the surface quality, Ra, and better results were found using vegetal base oil + 20% of graphite; as to the cutting force, the lubricants produced the lowest values.
Emmanuel O. Ezugwu, Rosemar B. Da Silva, John Bonney, Eder S. Costa, Wisley F. Sales and Alisson R. Machado
Journal of Manufacturing Science and Engineering, Transactions of the ASME, ISSN: 10871357, eISSN: 15288935, Volume: 141, Published: 1 January 2019 American Society of Mechanical Engineers (ASME)
This work presents the evaluation of three commercially available coolant grades (dicyclohexylamine-based coolant, a triethanolamine-based coolant, and an ester-based coolant) when machining Ti-6Al-4V alloy with high-pressure coolant delivery. The evaluations were based on tool life, tool failure modes, surface integrity, and chip formation. The dicyclohexylamine-based coolant was the more effective coolant when machining at the highest pressure of 20.3 MPa due to its stability at elevated temperature, whereas the triethanolamine-based coolant performed effectively at a pressure of 11 MPa due to its low surface tension properties. Deterioration of the ester-based coolant was found in almost all coolant pressures due to its low resistance to oxidation. Surfaces generated when machining with all coolants grades were generally acceptable with negligible physical damage.
José A. G. de Sousa, Wisley Falco Sales, Wilson L. Guesser and Álisson R. Machado
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 9-12, Pages: 2505-2517, Published: 1 October 2018 Springer London
Continuous bars of ductile iron are widely used for parts produced by machining processes, for example, hydraulic manifolds, hydraulic cylinder pistons, bushings, and pump housings. The main reasons for the selection of ductile iron bars are the high strength, stiffness, toughness, wear resistance, cost, and machinability. Concerning this last property, the best machinability is obtained for a ductile iron with a predominantly soft ferritic matrix. The rate of the solid-state transformation of austenite into ferrite, the so called “stable eutectoid reaction,” is dependent on the diffusion distance from the austenite to graphite particles, in other words, on the maximum distance between the graphite particles. If this distance increases, the time for the reaction may not be sufficient, and a “metastable eutectoid reaction” can occur, with the decomposition of austenite into pearlite, a mixture of soft ferrite with iron carbide. This constituent, called pearlite, shows higher hardness than ferrite, and so it must be machined under different conditions compared with a ferrite matrix. Thus, the distance between the graphite particles, measured by the number of graphite particles per unit area, determines the type of ductile iron matrix. The number of graphite particles is governed mainly by the solidification speed. In the continuous casting of bars of ductile iron, there is a variation in the solidification speed from the surface of the bar to the center of the section, decreasing toward the center. This is particularly important in thick sections, where the difference in the solidification speed is significant, leading to a variation in the microstructure from the surface to the center. This variation in the microstructure was the focus of this study, measuring various parameters connected to machinability, such as torque, power consumption, tool life (with tool wear analysis), and surface roughness. The goal was to show that the machining conditions must be changed when machining different positions on the section of a thick continuous ductile iron bar. Lower torque and shorter tool life were obtained when cutting the core in relation to the periphery region. However, in terms of power consumption and surface roughness, there was no statistical difference between the regions evaluated during the milling process. The variability of the machining output parameters is related to the mechanical properties along the cross section of the bars.
José Aécio G. de Sousa, Wisley Falco Sales and Alisson R. Machado
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 9-12, Pages: 4073-4092, Published: 1 February 2018 Springer London
Nowadays, the search for new materials is concerning to reduce the relative “efficiency/weight” ratio and its costs, in general, in the whole manufacturing chain, since the design until the final manufacturing stage. The efforts to achieve these requirements must fall in one of two options: (i) selecting “new” materials with similar strength of the “old,” but with low density or (ii) increasing the strength of the existing materials by adding alloying elements or by heat treatment. Choosing the best material for a given application depends on a few parameters such as mechanical loads, thermal environments, manufacturing costs, recycling, public acceptance, and workability. Among several kinds of materials are the cast irons, which almost always provide good machinability and low production cost. Under the scenario of the Industrial Revolution to date, cast iron received great emphasis on its development from the point of view of its properties and economic advantages. Currently, among the metallic materials, cast irons are the second most produced, after steels. They are an extremely important group of metal for the industry because, by introducing alloying elements and applying appropriate heat treatment, their use has become viable in some applications that were exclusively of steels. The several grades and groups available, on the other hand, brings another concern about their machinability. After production on the foundry, cast irons always are processed by machining, involving a large amount of money. With the goal of bringing relevant information on the machinability characteristics of cast irons, this review was produced. It covers the main output parameters in machining (forces and power consumption, cutting temperature, surface roughness, recommended cutting tools, tool wear, and corresponding use of computational modeling technique, by using the finite element method) finalizing with future trends. It is hoped to fill a gap in the literature for those involved with machinability of this important metal.
Leonardo Rosa Ribeiro Da Silva, Antonio Favero Filho, Eder Silva Costa, David Fernando Marcucci Pico, Wisley Falco Sales, Wilson Luiz Guesser and Alisson Rocha Machado
Procedia Manufacturing, eISSN: 23519789, Pages: 474-484, Published: 2018 Elsevier B.V.
Abstract With the increasing demand for greater fuel efficiency, automotive companies urge to develop new and more efficient engines. In order to withstand the high compression rates and temperatures at which these super engines are subjected to, vermicular cast iron or compacted graphite iron (CGI) has been identified as the most suitable material to replace gray cast iron (LCI) in the production of engine blocks and cylinder heads. However, compacted graphite iron needs different machining conditions when compared to gray cast iron, therefore studies of the various output parameters involved in the machining of this material are important. This paper studies the influence of the cutting conditions (cutting speed and feed rate) on the average machining temperature near to the cutting zone using an infrared thermal camera in the end milling process of high strength CGIs. The surface roughness and power consumption were also monitored. The results showed that the cutting speed has a greater influence than the feed rate on the average cutting temperature, mainly due to the higher energy provided to the system when the cutting speed is increased. The increase in the feed rate generates more heat and greater temperature variability in the cutting zone, since the thicker chip sizes have more influence in the heat dissipation from the cutting zone. It is also observed that the material characteristics had more influence in the temperature of the regions near to the cutting zone than the machining parameters.
73rd Society of Tribologists and Lubrication Engineers Annual Meeting and Exhibition 2018, Pages: 191-199, Published: 2018
Julius Schoop, Wisley Falco Sales and Jawahir
Journal of Materials Processing Technology, ISSN: 09240136, Volume: 250, Pages: 1-8, Published: December 2017 Elsevier Ltd
Abstract In this work, Ti-6Al4 V alloy was machined using polycrystalline diamond (PCD) tools under three different cooling/lubricating environments: cryogenic cooling (liquid nitrogen (LN 2 ) at −195.8 °C), hybrid cooling/lubrication ( LN 2 and oil based MQL − minimum quantity lubrication) as well as conventional flood cooling (emulsion). The machining parameters were selected to achieve very low kinematic surface roughness ( f = 0.01 mm/rev, a p = 0.1 mm) and three cutting speeds of v c = 120, 240 and 360 m/min were evaluated. The as-machined surface integrity was compared for all conditions, showing significant improvements in surface and sub-surface properties with both cryogenic and hybrid cooling as compared to flood cooling. Although the PCD tools are not commonly used in high speed machining of Ti alloys because of the problem of thermally induced chemical wear, it was found that with the use of cryogenic cooling, the tribological system changed sufficiently to allow for sustained machining performance, with very low tool-wear ( VB C(cryogenic) v c = 240 m/min). Surface roughness values were as low as R a = 40 nm for cryogenic machining. Interestingly, flood machining did not lead to reduce surface roughness values. However, hybrid cooling/lubrication did yield the lowest cutting forces compared to both flood and cryogenic conditions. All conditions evaluated during this study resulted in cutting forces of less than 15 N, suggesting that cryogenic precision machining with PCD tools may be a suitable alternative to grinding, even for slender and thin-walled components.
Rosemar B. Da Silva, Wisley F. Sales, Eder S. Costa, Emmanuel O. Ezugwu, John Bonney, Márcio B. Da Silva and Álisson R. Machado
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 5-8, Pages: 1893-1902, Published: 1 November 2017 Springer London
The main focus of this study is to investigate the behaviour of cemented carbide tools and the surface integrity obtained when turning Ti-6Al-4V alloy. Machining trials were carried out with emulsion cutting fluid applied under conventional and high-pressure supplies and also in an argon-enriched environment. Tool life, cutting force, surface roughness, micrograph and microhardness beneath machined surface were evaluated for better understanding the relationship between the fluid environment and the surface integrity of the machined workpiece. Machining with high-pressure coolant supply generated the best tool life results, while enriched argon showed lower tool life because of the lower conductivity and poor lubrication characteristics of argon gas that lead to heat to be more concentrated at the cutting area, thus weakening the strength of the cutting tool and accelerating tool wear. No plastic deformation was observed on the machined surfaces under the conditions investigated. However, there was evidence of surface hardening after machining with conventional and in an argon-enriched environment due to the poor cooling function of argon. Surface hardening was minimal after machining with high-pressure coolant supplies.
Antônio Santos Araújo Junior, Wisley Falco Sales, Rosemar Batista da Silva, Eder Silva Costa and Álisson Rocha Machado
Journal of Cleaner Production, ISSN: 09596526, Volume: 156, Pages: 635-647, Published: 10 July 2017 Elsevier Ltd
Abstract The focus of this study is the search for cutting fluids that are not toxic to humans or damaging toward the environment, with a view to sustainable manufacturing. The technical viability of the use of biodegradable natural vegetable oils as cutting fluids in the milling of AISI 1045 steel was evaluated applying the minimum quantity of lubricant (MQL) technique. The edible vegetable oils studied were cottonseed, babassu nut, canola, sunflower, corn and soybean. For comparison purposes, the commercial vegetable-based fluid LB 2000 (not edible) was considered, applying the same MQL technique, in addition to the dry condition as a benchmark. The fluids were firstly submitted to specific tests to quantify their lubri-cooling capacity as well as their physical and chemical properties. Based on the results obtained in each test the fluids were ranked. The two edible oils with the best results for cooling ability were cottonseed and canola and these were applied in tests to study the tool life during milling, using coated cemented carbide tools. After milling, the tools were analyzed by scanning electron microscopy to examine the wear mechanisms. Cottonseed and canola oils showed promising results, particularly considering that they are non-toxic towards humans and non-polluting in the environment. Adhesion or attrition (stick-slip phenomenon) was the dominant wear mechanism encountered, regardless of the oil tested.
Emmanuel O. Ezugwu, Rosemar Batista Da Silva, Wisley Falco Sales, and Alisson Rocha Machado
Encyclopedia of Sustainable Technologies, Pages: 487-506, Published: 4 July 2017 Elsevier
Machining of titanium alloys has always attracted considerable great interest in the manufacturing sector as well as within the scientific research community worldwide. Titanium alloys are widely employed in aero-engine and for airframe manufacture because of their outstanding strength to density ratios relative to other materials. Due to the expensive cost of titanium alloys, relative to other metals, attributed mainly to the complexity of the extraction process, difficulty of melting and problems during fabrication and machining, integrated researches have been established globally to improve their machinability. Success in the machining of titanium alloys can be achieved by employing the correct selection of cutting tools, cutting environment, and appropriate cutting conditions for each machining operation. This article reviews the machining of titanium alloys, highlighting the main cutting tools, cutting parameters, and cooling environments that have been employed in last three decades. The purpose is to enhance the general understanding of practitioners and researchers on the principles of machining titanium alloys, the properties that impair their machinability, performance of different cutting tools, wear mechanisms, and dominant failure modes of cutting tools under different machining conditions, including various techniques that enhance the machining of titanium alloys. A good understanding of these parameters as well as processing time and functionality of the machined component will lead to efficient and economic machining of titanium-base superalloys.
Rogério Felício dos Santos, Ernane Rodrigues da Silva, Wisley Falco Sales and Alberto Arnaldo Raslan
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 5-8, Pages: 2001-2007, Published: 1 May 2017 Springer London
Among the various processes that produce enrichment on metal surfaces, there are those that use nitriding through electrical discharge machining (EDM). In this process, the nitrogen source is an aqueous solution of water and urea. The objective of this study is to show the influence exerted by the electrode material in EDM through the nitriding process of AISI 4140 steel. The authors performed tests through use of a sink EDM machine. The dielectric fluid used in the experiments was deionized water solution containing 10 g/l of commercially available urea. The electrodes were made up of copper and graphite. The samples characterization analysis was performed through x-ray diffraction (XRD), optical microscopy, and microhardness. This procedure demonstrated, in both electrodes, the formation of a hardened layer with a thickness around 20 μm. There was no difference in the hardness of the samples when using different electrodes. The constituting materials of the electrodes act in the process where copper and carbon are transferred onto the surface of the steel. When using the copper electrode, one observes the formation of nitrides. In addition, with the graphite electrode, one observes the formation of iron carbide and nitride γ′. These differences were attributed to changes in the thermodynamic process.
Rogério Felício dos Santos, Ernane Rodrigues da Silva, Wisley Falco Sales and Alberto Arnaldo Raslan
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 1-4, Pages: 1251-1257, Published: 1 March 2017 Springer London
The process of nitriding with electrical discharges makes use of electrical discharge machining (EDM) machines. Nitrogen is supplied by a dielectric fluid comprised of distilled water or deionized and urea solution (CH4N2O). The underlying objective of this study was to investigate the influence connected to the amount of urea diluted in deionized water during the nitriding process of AISI 4140 steel. The tests were performed using a sinker EDM machine. As a tool electrode, the authors used an electrolytic copper cylinder, and as workpiece electrodes, they used cylindrical AISI 4140 steel. Samples of deionized water were used as a dielectric fluid and urea was added at different concentrations. The results showed the progressive loss of dielectric strength with the addition of different amounts of urea, mixed to the water. There was also a noticeable change in the kinetics of the plasma channel formation. Urea quantities higher than 10 g/l did not produce correct plasma arc formation. Variations in urea content did not significantly change in the morphology of the machined surface, the thickness of the nitrided layer, the type of nitrides formed, or the final hardness of the enriched surfaces. However, the increase in the amount of urea caused the loss of dielectric strength of the fluid with a consequent decrease in the material removal rate and therefore, the best material removal rate (MRR) was found when machined at a lower urea content level.
Wisley Falco Sales, Julius Schoop and Jawahir
Tribology International, ISSN: 0301679X, Volume: 114, Pages: 109-120, Published: 2017 Elsevier Ltd
Abstract This work aims at studying wear and its inherent mechanisms, which are present during the process of machining Ti6Al4V alloy, using PCD (Polycrystalline Compact Diamond) tools under superfinishing conditions set within the following environments: cryogenic (liquid N 2 ), hybrid (liquid N 2 + fluid at minimal quantity of lubricant – MQL) and flood (vegetable fluid). The machining process was performed under the following conditions: feed rate 0.01 mm/rev, depth of cut 0.1 mm and cutting speed 240 m/min. The results obtained show that the flank and crater wear was of dominant wear shapes. Adhesion followed by the plucking out of hard diamond grains and their movements over the tool rake face produced the abrasive wear, these were also observed in flood conditions.
Fábio F. Lima, Wisley F. Sales, Eder S. Costa, Flávio J. da Silva and Álisson R. Machado
Ceramics International, ISSN: 02728842, Pages: 677-685, Published: 1 January 2017 Elsevier Ltd
Abstract The aim of this work is to study the tool life and wear (types and mechanisms) experienced by ceramic tools (SiAlON, whisker and mixed ceramic) when turning the nickel-based superalloy Inconel 751 using argon and oxygen atmospheres. This material is largely used as inlet and outlet gas valves in Otto and Diesel cycle engines. Design of experiment (DOE) planning techniques were used with the following input variables: tool materials [SiAlON (Si 3 N 4 +Al 2 O 3 ), Whisker (Al 2 O 3 +SiC w ) and Mixed (Al 2 O 3 +TiC)], cutting speed, tool geometry and lubri-cooling atmosphere (dry cutting as a benchmark, followed by argon- and oxygen-enriched atmospheres). These atmospheres support sustainable manufacturing, in contrast to common practices in which cutting fluids are considered a polluting component. In each machining test, a new tool edge was used through the end of the tool life, with interruptions conducted for wear measurements. At the end of the tests, the tools were analysed by optical and scanning electron microscopy. The results indicated that the cutting speed, tool geometry and lubri-cooling atmosphere influence the types of wear and the tool life. Notch wear (VB N ), average flank wear (VB B ) and nose wear (VB C ) prevailed and depended on the cutting conditions and tool material. Overall, the SiAlON tools exhibited the best tool life performance, followed by the mixed and whisker ceramics. The lowest tool life was observed for whiskers in dry conditions. Notch wear was accelerated by an oxygen-rich atmosphere, particularly at low cutting speeds. Attrition and chipping were the dominant wear mechanisms.
Sales, Oliveira and Raslan
Surface and Coatings Technology, ISSN: 02578972, Volume: 307, Pages: 1011-1015, Published: 15 December 2016 Elsevier B.V.
Abstract The use of the energy generated in machining processes by electrical discharge (EDM) to enrich metal surfaces with nitrogen is already well known, and following on from this research focus, the aim of this study is to evaluate the possibility of enrichment through this process, for the surface of Ti6Al4V alloy with titanium perovskite. The resulting surface shows high biocompatibility with human bone and teeth and becomes essential as a biomedical material. Tests were performed using a sink EDM process and as a dielectric fluid, an aqueous solution of calcium chloride was used. The samples characterizations were made using the scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), optical microscopy and Knoop microhardness. The results showed the formation of an uneven surface enriched with calcium, in the form of titanium perovskite. On the lateral section of the sample one notes the formation of a porous layer. Beneath this, a uniform hardened layer was formed, extending to a depth of approximately 200 μm below the surface. Calcium insertion into the Ti6Al4V surface was attributed to the occurrence of re-solidification and ion implantation. It can be concluded that it is feasible to enrich, by EDM, the surface of a Ti6Al4V alloy with titanium perovskite.
Luiz Carlos da Silva, Paulo Rosa da Mota, Márcio Bacci da Silva, Wisley Falco Sales, Álisson Rocha Machado and Mark James Jackson
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 9-12, Pages: 3485-3496, Published: 1 December 2016 Springer London
Burrs formed during the machining process is considered a major problem in the manufacturing industry because they can impair mechanical assemblies, change the dimensions of the machined products, and compromise the physical integrity of the operators, among many other inconveniences. Therefore, burrs should be avoided but if formed their dimensions should be minimized. In this work, the burr dimensions were investigated, and the cutting conditions that minimize them were determined using a central composite design (CCD) and response surface methodology (RSM) in face milling of PH 13-8 Mo stainless steel with coated carbide inserts. Burr formed on the workpiece exit edge and the behaviors of its height during the manipulation of the evaluated variables (tool exit angle from the workpiece, cutting speed, feed per tooth, axial depth of cut and average tool flank wear) were analyzed. The burrs were indirectly measured, where replicas of the workpiece edges (with their burrs) were produced with condensed silicone. The results showed that there is a considerable reduction in the burr height when lower exit angles and new cutting tools are used. The minimum number of burrs is produced when using increasing feed per tooth and decreasing axial depth of cut. The cutting speed presented negligible influence on the height of the burr.
Luciano José Arantes, Ernane Rodrigues da Silva, Rogério Felício dos Santos, Wisley Falco Sales and Alberto Arnaldo Raslan
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 1-4, Pages: 411-420, Published: 1 October 2016 Springer London
The purpose behind this work was the development of a hybrid methodology, which combines the electrical fischarge machining (EDM) with a high-pressure jet of dielectric fluid mixed with abrasive powder. The low MRR (material removal rate) observed on the EDM is, undoubtedly, one of the most important limitations of this process, especially today, where competitiveness among the enormous varieties of machining processes has attained an unbelievable level of speed and surface finishing. A special device was built in order to provide and apply the high-pressure abrasive jet. Cooper tube-shaped tools were used for the experiments and the machined material consisted of commercial high-speed steel (AISI M2). Kerosene, deionized water, and mineral-based oil were used as dielectric fluids and the abrasive was constituted of SiC (600 mesh), with jet pressures varying from zero to 100 bar, and abrasive concentration kept fixed at 30 g/l. The results show an eightfold increase in MRR when the EDM process is aided by abrasive particles. Furthermore, remarkable gains were obtained with kerosene and deionized water, both with enhanced surface finishing. Therefore, this new process, denominated as abrasive jet electrical discharge machining (AJEDM), proves to be efficient for increasing machining velocity while decreasing the surface roughness and its use has shown itself to be technically viable.
Mário C. Santos, Alisson R. Machado, Wisley F. Sales, Marcos A. S. Barrozo and Emmanuel O. Ezugwu
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 9-12, Pages: 3067-3080, Published: 1 October 2016 Springer London
The use of aluminum alloys in manufacturing industry has increased significantly in recent years. This is because primarily to their ability to combine lightness and strength in a single material. Concomitant to this growth, the machining of aluminum alloys has enormously increased in volumetric proportions—so that the chip volume represents up to 80 % of the original volume of the machined material in certain segments of the industry, like aerospace. In this context, knowledge of the characteristics of machinability of aluminum alloys is essential to provide industry and researchers with information that allows them to make the right decisions when they come to machining this fantastic material. The purpose of this review is to compile relevant information about the characteristics of machinability of aluminum alloys into a single document.
Igor Cézar Pereira, Marcio Bacci Da Silva, Daniel Fernandes Da Cunha and Wisley Falco Sales
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 5-8, Pages: 1041-1048, Published: 1 February 2016 Springer-Verlag London Ltd
The main objective of this work is to investigate the tapping operation of cast iron when varying the cutting speed and the method of application of cutting fluid, monitoring tool wear, torque, and axial force during the operation. Two types of gray cast iron were evaluated: CrCuSn alloy, FC 250; CrCuSnMo alloy, FC 300, and compacted graphite iron machine tool, FV 350. Tests were performed at two lubrication/cooling conditions: in the first one, it was applied an emulsion of water and oil; in the second one, the fluid was applied in minimal quantity (MQF), at pressure of 6.0 bar and intermittent spray at a frequency of 1 pulse/s, resulting in a flow rate of 30 ml/h. For MQF condition, a vegetable oil was used. Torque, axial forces, and tool wear were measured during the operation. Statistical analysis showed that the cutting speed was the parameter that most influences the torque, followed by the cutting fluid and the material hardness.
Rogério F. Santos, Ernane R. Silva, Wisley F. Sales and Alberto A. Raslan
Procedia CIRP, ISSN: 22128271, Pages: 303-306, Published: 2016 Elsevier B.V.
Abstract The aim of this this work is to demonstrate the feasibility of nitriding AISI 4140 steel using electric discharges produced by sink EDM equipment. This was performed using a copper electrode, and mixed deionized water and urea as the dielectric fluid. Techniques such as laser profilometry, x-ray diffraction (XRD), glow discharge optical emission spectroscopy (GDOES), scanning electron microscopy (SEM) and optical microscopy were employed. The proposed mechanism for this particular nitriding process was that of ion implantation and the layer under scrutiny was shown to have been hardened, however coming to beneath of the surface the hardness decreases, which coincides with the impoverishment of the quantity of nitrogen inserted.
Armando Marques, Cleudes Guimarães, Rosemar Batista da Silva, Maria da Penha Cindra Fonseca, Wisley Falco Sales and Álisson Rocha Machado
Procedia Manufacturing, eISSN: 23519789, Pages: 609-620, Published: 2016 Elsevier B.V.
Nickel-based superalloys have been widely employed in the aerospace industry because of their high mechanical strength that is maintained even at elevated temperatures. However, because of their outstanding properties they are considered difficult-to-machine material. Thus, any attempt to improve machining productivity of such material is encouraged. Since they are used in components with great technical responsibility, microstructure and residual stress changes caused by machining should be monitored. This paper presents a study of the surface integrity (roughness, microstructure, microhardness and residual stress) in turning of Inconel 718 with solid lubricants (graphite and molybdenum disulfide - MoS2) dispersed in oil that were delivered in the cutting zone by the MQL technique. Addition of graphite in the oil improved the tool life but the same did not occur with MoS2. No significant microstructural changes were observed on the machined surfaces with the addition of solid lubricants. Negligible influence of them in surface roughness and residual stresses was noticed after machining Inconel 718 under different cutting conditions.
Luis Henrique Andrade Maia, Alexandre Mendes Abrao, Wander Luiz Vasconcelos, Wisley Falco Sales and Alisson Rocha Machado
Tribology International, ISSN: 0301679X, Pages: 519-532, Published: 27 December 2015 Elsevier Ltd
Abstract A methodology for detection of wear mechanisms and determination of end of life of the cutting tool based on the acoustic emission signals is proposed, using an innovative technique. With this technique, the AE signals generated in hardened AISI 4340 steel turning respond well to the tool wear evolution. The tests were made using common and nanostructured AlCrN coated and uncoated cemented carbide tools. The AE signal spectrum is correlated with the wear mechanisms identified in the cutting tools and compared to the excitation frequency values corresponding to the respective mechanisms validating the identification of the wear mechanisms. The evolution of maximum flank wear resulted in increasing amplitude of average of Power Spectral Density at the end of life.
Ricardo R. Moura, Márcio B. da Silva, Álisson R. Machado and Wisley F. Sales ISSN: 00431648, Volume: 332-333, Pages: 762-771, Published: May 01, 2015 Elsevier Ltd
Abstract The process of machining of hard materials such as titanium and its alloys, has an important role in the development of new machining techniques, such as cutting tools and coatings, with the aim to increase the machinability of these materials. Due to the poor thermal properties of the titanium, the cutting tool suffers accelerated wear which affects the tool life. This paper describes a study of the use of solid lubricant during the machining of Ti-6Al-4V in a turning operation. TiAlN (PVD) coated cemented carbide tool (class S15) was used. Dry tests, tests with lubricant and tests with lubricant with 20% by weight of solid lubricants: graphite mesh 325 (average particle size of 40 μm), graphite mesh 625 (20 μm) and molybdenum disulphide (MoS 2 , 6 μm) were made. The output parameters are: tool life, surface roughness, cutting force and interfacial temperature (tool-work thermocouple). Tool flank wear, a major problem in machining of titanium alloys, was significantly reduced due to the action of the solid lubricants. Experimental results showed the superiority of molybdenum disulphide in relation to graphite in the turning process: reducing the tool wear, prolonging the tool life and improving the surface roughness. The solid lubricant may be a viable alternative to dry and wet turning. Thus, it may be inferred that proper application of solid lubricants in machining of Ti-6Al-4V alloy results in reduction in tool wear, which can lead to enhancement of productivity.
Rhander Viana, Milton Sérgio Fernandes de Lima, Wisley Falco Sales, Washington Martins da Silva and Álisson Rocha Machado
Surface and Coatings Technology, ISSN: 02578972, Volume: 276, Pages: 485-501, Published: 25 August 2015 Elsevier
Abstract In machining, a laser beam with a high density of energy can be used to promote nano- or microstructural surface changes of the substrate of the tools with the goal of improving the adhesion of the coatings. The detachment and fragmentation of coatings during machining will compromise tool performance by the premature exposition of the substrate and may cause wear by fragments of hard and abrasive particles. The goal of this study is to test this new technology of laser texturing of cemented carbide inserts of ISO K grade before coating them with TiAlN and AlCrN. The performance of these laser-textured tools was compared with that of microblasted tools (the commercial technique normally used). Tool life tests in face milling of compacted graphite cast iron (CGI, grade 450) were carried out and the adhesion of the coated layers to the substrates of the tools was characterized by Rockwell indentation tests and scratch tests with a progressive load. The tool life results showed that the laser-textured tools outperformed the microblasted commercial cutting tools under the conditions tested. The adhesion results measured by scratch and Rockwell indentation tests showed greater delamination of the microblasted tools than of the laser-textured tools.
Rosemar B. Da Silva, Álisson R. MacHado, Emmanuel O. Ezugwu, John Bonney and Wisley F. Sales
Journal of Materials Processing Technology, ISSN: 09240136, Volume: 213, Pages: 1459-1464, Published: 2013 Elsevier Ltd
Abstract Usage of titanium alloys has increased since the past 50 years despite difficulties encountered during machining. Many studies involving different tool materials, cutting parameters, tool geometry and cutting fluids when machining this important aerospace material have been published. However, there are relatively few literatures available on the application of ultra hard tools in the machining of titanium-alloys. The primary objective of this study is to investigate the behaviour of Polycrystalline Diamond (PCD) tools when machining Ti–6Al–4V alloy at high speed conditions using high pressure coolant supplies. Tool performance under different tribological conditions and the dominant wear mechanisms were investigated. Increase in coolant pressure tends to improve tool life and reduce the adhesion tendency, accelerated by the susceptibility of titanium alloy to gall during machining. Adhesion and attrition are the dominant wear mechanisms when machining at the cutting conditions investigated.
Dental Press Journal of Orthodontics, ISSN: 21769451, eISSN: 21776709, Published: November 2012
Journal of Applied Sciences Research, ISSN: 1816157X, eISSN: 1819544X, Pages: 757-764, Published: July 2009
Wisley Falco Sales, Marcelo Becker, Alexandre G. Gurgel and Jánes L. Júnior
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 9-10, Pages: 873-882, Published: June 2009 Springer Science and Business Media LLC
Conventional threading operations involve two distinct machining processes: drilling and threading. Therefore, it is time consuming for the tools must be changed and the workpiece has to be moved to another machine. This paper presents an analysis of the combined process (drilling followed by threading) using a single tool for both operations: the tap-milling tool. Before presenting the methodology used to evaluate this hybrid tool, the ODS (operating deflection shapes) basics is shortly described. ODS and finite element modeling (FEM) were used during this research to optimize the process aiming to achieve higher stable machining conditions and increasing the tool life. Both methods allowed the determination of the natural frequencies and displacements of the machining center and optimize the workpiece fixture system. The results showed that there is an excellent correlation between the dynamic stability of the machining center-tool holder and the tool life, avoiding a tool premature catastrophic failure. Nevertheless, evidence showed that the tool is very sensitive to work conditions. Undoubtedly, the use of ODS and FEM eliminate empiric decisions concerning the optimization of machining conditions and increase drastically the tool life. After the ODS and FEM studies, it was possible to optimize the process and work material fixture system and machine more than 30,000 threaded holes without reaching the tool life limit and catastrophic fail.
Sales, Costa, Santos, Diniz, Bonney and Ezugwu
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 7-8, Pages: 660-669, Published: April 2009 Springer Science and Business Media LLC
TiN-coated cemented carbide, mixed ceramic and PCBN with a high percentage of CBN (PCBN-H) tools were used for reconditioned turning of hardened and tempered W320 steel hot working dies. The dies are usually scraped after their useful life because they are difficult to be reconditioned by machining. One alternative to scraping these dies is to convert them, increasing their internal diameters by internal turning. The machining experiments showed that coated carbide tools performed better at cutting speeds up to 120 m/min, while PCBN tools were superior at higher speeds up to 200 m/min. Mixed ceramic tools did not perform well under the conditions investigated. The tribological system showed abrasion, adhesion and plastic deformation as the dominant wear mechanisms. Chipping on the tool rake and flank faces, as well as catastrophic failure, was also observed in some experiments.
Wisley Sales, Marcelo Becker, Clovis S. Barcellos, Janes Landre Jr., John Bonney and Emmanuel O. Ezugwu
Industrial Lubrication and Tribology, ISSN: 00368792, Pages: 84-90, Published: 6 March 2009 Emerald
Purpose – The purpose of this paper is to evaluate the performance of cutting fluid applied by minimum quantity technique when milling AISI 4140 steel with TiAlN coated cemented carbide inserts.Design/methodology/approach – The vegetable oil based cutting fluid evaluated was applied through a nozzle at the centre of the tool holder under vaporized conditions with a flow rate between 0 (dry cutting) and 200 ml/h, at 50 ml/h increments. Tool wear (based on maximum flank wear, VBmax), surface roughness parameters (Ra and Rt) and burr formation (length of burr, h) were recorded and evaluated. Scanning electron microscope images and energy dispersive X‐ray analysis of the worn tools show adhesion as the dominant wear mechanism.Findings – Encouraging tool performance was recorded when milling AISI 4140 steel due to improved lubrication and cooling at the cutting interfaces. Increase in cutting fluid flow rate improves tool life with gradual reduction of the surface roughness parameters and negligible influence ...
Karina S. S. Lopes, Wisley Falco Sales and Ernani S. Palma
Journal of the Brazilian Society of Mechanical Sciences and Engineering, ISSN: 16785878, eISSN: 18063691, Pages: 77-83, Published: January/March 2008 Brazilian Society of Mechanical Sciences and Engineering
The general purpose of this research is to study the influence of commercial machining parameters on fatigue limits of steels. Specifically in this work, the influence of cutting speeds, depth of cut, feed rate and residual stresses of turned surfaces of AISI 4140 steel specimens on fatigue strength were analyzed. In some specimens, the residual stress was eliminated by heat treatment. The fatigue experiments were carried out at room temperature, applying a cyclical frequency of 58Hz, with mean stress equal to zero (R=-1), on a rotating-bending fatigue testing machine of the constant bending moment type. It was used the staircase (or up-and-down) method to determine the fatigue limit of the specimens.
Wisley F. Sales, Álisson R. Machado, John Bonney and Emmanuel O. Ezugwu
Journal of the Brazilian Society of Mechanical Sciences and Engineering, ISSN: 16785878, eISSN: 18063691, Pages: 372-378, Published: October/December 2007 Brazilian Society of Mechanical Sciences and Engineering
This work demonstrates that scratch test techniques can be used to provide a quick and cost effective evaluation of cutting fluids. Apparent coefficient of friction and specific energy for the scratch steel samples under several lubrication conditions provides a good indicator of cutting fluid performance. This is followed by evaluation of the surface finish and the cutting force of the ABNT NB 8640 steel with emulsion and synthetic cutting fluids, at 5% of concentrations, and neat mineral oil in the turning process. Comparative tests were carried out under dry and wet conditions. Results show that the linear scratch test was not efficient while the pendular scratch test was efficient tool in the classification of cutting fluids. The results can be transferred to conventional machining due to its dynamic nature.
Dos Santos, Sales, Santos, MacHado, Da Silva, Bonney and Ezugwu
International Journal of Advanced Manufacturing Technology, ISSN: 02683768, eISSN: 14333015, Issue: 7-8, Pages: 629-637, Published: January 2007 Springer Science and Business Media LLC
Two PVD coated powder metallurgy high speed steel (PM-HSS) gear cutters were investigated when machining helical gears made from AISI 19MnCr5 steel with hardness between 140 and 180 HV. Machining trials were carried out with gear cutters coated with TiAlN (nano layers) and TiN (mono layer). Crater and flank wears were measured and analysed after all the machining trials. Analyses of the worn tools show that the TiAlN coated gear cutter performed better than the TiN coated gear cutter. This can be attributed to its nano layers and the higher hardness of the TiAlN coating. The dominant tool wear mechanisms were adhesion, abrasion, delaminating of the coating layer and chipping of the cutting edge.
Gurgel, Sales, de Barcellos, Bonney and Ezugwu
International Journal of Machine Tools and Manufacture, ISSN: 08906955, Issue: 12-13, Pages: 1637-1642, Published: October 2006 Elsevier BV
Abstract The main objective of this study is to implement a parameter sensitivity analysis method to be used in the search of optimal machining conditions with respect to surface quality. Presently, the element-free Galerkin (EFGM) approximating functions are used to evaluate the properties of machined surfaces with cutting parameters when turning AISI 4140 steel using arbitrary sets of experimental values and the EFGM approximation functions, based on the moving least-squares method, in order to obtain the sensitivities through proper local derivations. This method shows the sensitivity of each surface parameter for each input variable. The variables investigated were cutting speed ( v c ), depth of cut ( a p ), feed rate ( f ) and the surface roughness ( R a ). The sensitivity results showed that the feed rate has the highest influence on surface roughness when turning AISI 4140 steel followed by cutting speed and depth of cut.
Ezugwu, Fadare, Bonney, Da Silva and Sales
International Journal of Machine Tools and Manufacture, ISSN: 08906955, Issue: 12-13, Pages: 1375-1385, Published: October 2005 Elsevier BV
Abstract An artificial neural network (ANN) model was developed for the analysis and prediction of the relationship between cutting and process parameters during high-speed turning of nickel-based, Inconel 718, alloy. The input parameters of the ANN model are the cutting parameters: speed, feed rate, depth of cut, cutting time, and coolant pressure. The output parameters of the model are seven process parameters measured during the machining trials, namely tangential force (cutting force, Fz), axial force (feed force, Fx), spindle motor power consumption, machined surface roughness, average flank wear (VB), maximum flank wear (VBmax) and nose wear (VC). The model consists of a three-layered feedforward backpropagation neural network. The network is trained with pairs of inputs/outputs datasets generated when machining Inconel 718 alloy with triple (TiCN/Al2O3/TiN) PVD-coated carbide (K 10) inserts with ISO designation CNMG 120412. A very good performance of the neural network, in terms of agreement with experimental data, was achieved. The model can be used for the analysis and prediction of the complex relationship between cutting conditions and the process parameters in metal-cutting operations and for the optimisation of the cutting process for efficient and economic production.
Ezugwu, Bonney, Fadare and Sales
Journal of Materials Processing Technology, ISSN: 09240136, Volume: 162-163, Issue: SPEC. ISS., Pages: 609-614, Published: 15 May 2005 Elsevier BV
Abstract Machining of Inconel 718 with whisker reinforced ceramic tool gave better performance in terms of tool life under high-pressure coolant supplies up to 15 MPa compared to conventional coolant supplies. The use of 15 MPa coolant supply pressure tend to suppress notching during machining thus improving tool life, while the use of higher coolant supply pressure of 20.3 MPa did not show improvement in tool life due probably to accelerated notch wear caused by water jet impingement erosion. Cutting forces decreased with increasing coolant supply pressure due to improved cooling and lubrication at the cutting interface as well as effective chip segmentation ensured by the momentum of the coolant jet. Surface roughness generated were well below the rejection criteria. This can be attributed to the round shape of the insert which tend to encourage smearing of the machined surface with minimum damage. Microstructure analysis of the machined surfaces show evidence of plastic deformation and hardening of the top layer up to 0.15 mm beneath the machined surface as a result of increase in dislocation density.
Nascimento Jr., Santos, Sales and Palma
Journal of Testing and Evaluation, ISSN: 00903973, Pages: 168-173, Published: May 2005 ASTM International
Antônio Maria De Souza Jr., Wisley Falco Sales, Sandro Cardoso Santos and Alisson Rocha MacHado
International Journal of Machine Tools and Manufacture, ISSN: 08906955, Pages: 335-344, Published: March 2005 Elsevier BV
Abstract In this work two face milling cutter systems were used in high speed cutting of gray cast iron under cutting condition encountered in the shop floor. The first system, called ‘A’, has 24 Si3N4 ceramic inserts all with square wiper edges. The second system, called ‘B’, is a mixed tool material system, having 24 wiper inserts, 20 of them are Si3N4 intercalated by four PCBN inserts. Cutting speed (vc), depth of cut (doc) and feed rate per tooth (fz) were kept constant. Surface roughness (Ra and Rt) and waviness (Wt), tool life (based on flank wear, VBBmax) and burr formation (length of the burr, h) were the parameters considered to compare the two systems. System ‘B’ presented better performance according to all parameters, although only end of life criterion based on Rt parameter has been reached.
Dirley Carlos Corrêa, Wisley Falco Sales, Sandro Cardoso Santos and Ernani Sales Palma
Journal of Materials Processing Technology, ISSN: 09240136, Volume: 159, Pages: 435-444, Published: 10 February 2005 Elsevier BV
Abstract This text presents informations regarding the complexity of simultaneously machining two distinct materials: GH190 gray cast iron and Fe–C–Cu steel alloy, being the latter obtained through powder metallurgy. The machining of the bearings in the cylindrical boring process using cemented carbide tools coated with titanium nitride (TiN) has also been evaluated. The feed rate has been varied while the other parameters, such as cutting speed and depth of cut, were kept fixed. After the flank wear on the tools was monitored it was possible to conclude that for a certain number of workpieces machined, the wear process on the tools was less severe when the feed rate was increased. The worn surfaces were analyzed with an electronic microscope. High levels of adherence have been observed and the main wearing mechanisms were adhesion, diffusion and attrition.
E. O. Ezugwu, J. Bonney, W. F. Sales, and R. B. da Silva
Proceedings of the World Tribology Congress III - 2005, Pages: 913-914, Published: 2005 ASMEDC
Usage of titanium alloys has increased since the past 50 years despite difficulties encountered during machining. In this study PCD tools were evaluated when machining Ti-6Al-4V alloy at high speed conditions under high pressure coolant supplies. Increase in coolant pressure tend to improve tool life and minimise adhesion of the work material on the cutting tool during machining. Adhesion can be accelerated by the susceptibility of titanium alloy to galling during machining.
Sandro Cardoso Santos, Wisley Falco Sales, Flávio José da Silva, Sinésio Domingues Franco and Marcio Bacci da Silva
Surface and Coatings Technology, ISSN: 02578972, Volume: 184, Issue: 2-3, Pages: 141-148, Published: 22 June 2004 Elsevier BV
This work compares different coatings deposited on HSS and carbide drills using two different approaches. Tool life is measured during cutting tests when machining a grey cast iron. The parameter used to measure tool life is the number of holes per thickness of the coating. The results are then compared with the wear resistance coefficient of the coating, obtained after a micro-scale abrasive test. Four types of PVD coatings deposited on HSS and tungsten carbide drills are used. The results have shown a good correlation between tool life and wear coefficients for all combinations of cutting tool and coating, mainly for cemented carbide drills.
Cláudio Araújo Rocha, Wisley Falco Sales, Clovis Sperb De Barcellos and Alexandre Mendes Abrão
Journal of Materials Processing Technology, ISSN: 09240136, Volume: 145, Pages: 397-406, Published: 1 February 2004 Elsevier BV
Abstract This research aims to investigate the influence of cutting speed ( v c ), depth of cut (doc) and feed rate ( f ) on the machining of valve seats of internal combustion engines using polycrystalline cubic boron nitride (PCBN) tools. The workpiece material was Fe–C–Cu–Ni–Mo alloy obtained from powder metallurgy technique. The quality of the resulting surface is fundamental for the performance of engines and was estimated by R a , R q , R z , R t and W t surface roughness parameters, while relations between surface and cutting parameters were performed. Among the cutting parameters the cutting speed was the most influent on the wear of the tools. The predominant types of wear were flank and crater, while mechanisms as attrition prevailed at low v c and diffusion at medium v c . The dynamic instability identified by accelerometers at the machine was decisive in leading to discontinuous chip flow and chipping phenomena due to low fracture toughness of tool material.
De Souza Júnior, Sales, Ezugwu, Bonney and Machado
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, ISSN: 09544054, Volume: 217, Pages: 1589-1596, Published: 2003 SAGE Publications
Abstract Two face milling cutter systems, both with PCBN (polycrystalline cubic boron nitride) tools, were used to study burr formation in high-speed machining of grey cast iron under various cutting conditions. Surface roughness parameters Ra and Ri, tool life (based on flank wear, VBmax) and burr formation (length of the burr, h) were recorded and used for comparing machining performance. The best performance in terms of tool life and surface roughness was obtained with the milling cutter system consisting of 24 teeth and 24 square wiper inserts. Machining with this cutter configuration produced acceptable surface roughness values, well below the rejection criterion, after machining a batch of 3000 motor blocks in addition to achieving a significant reduction in the burr length.
Industrial Diamond Review, ISSN: 00198145, Pages: 60-65, Published: 2003
Industrial Diamond Review, ISSN: 00198145, Issue: 595, Pages: 268-272, Published: 2002
Sales, Guimarães, Machado and Ezugwu
Industrial Lubrication and Tribology, ISSN: 00368792, Pages: 57-68, Published: 1 April 2002 Emerald
Many machining researches are focused on cutting tools mainly due to the wear developed as a result of high temperatures generated that accelerate thermally related wear mechanisms, consequently reducing tool life. Cutting fluids are used in machining operations to minimize cutting temperature although there is no available indicator of their cooling ability. In this study, a method to determine the cooling ability of cutting fluids is proposed. A thermocouple technique was used to verify the chip‐tool interface temperature of various cutting fluids during turning operation. The method consists of measuring the temperature drop from 300°C up to room temperature after heating a standardised AISI 8640 workpiece and fixing it to the chuck of a lathe and with a constant spindle speed of 150 rpm the cutting fluid was applied to a specific point. The temperature was measured and registered by an infrared thermosensor with the aid of an AC/DC data acquisition board and a PC. The convective heat exchange coeffici...
Sales, Diniz and Machado
Revista Brasileira de Ciencias Mecanicas/Journal of the Brazilian Society of Mechanical Sciences, ISSN: 01007386, Pages: 227-240, Published: 2001 Brazilian Society of Mechanical Sciences and Engineering
In the last decade a lot has been discussed about the suitability of using cutting fluid in abundance to cool and lubricate machining processes. The use of cutting fluid generally causes economy of tools and it becomes easier to keep tight tolerances and to maintain workpiece surface properties without damages. In the other hand, it brings also some problems, like fluid residuals and human diseases. Because of them some alternatives has been sought to minimise or even avoid the use of cutting fluid in machining operations. Some of these alternatives are dry cutting and cutting with minimum quantity of fluid (MQF). The main goal of this work is to discuss these tendencies. Therefore, topics like kinds and methods of applications of modern cutting fluids and what are new in this area will unavoidably be considered. MQF and dry cutting techniques, their applications and where it is not possible to apply them will also be focused. To exemplify the topics, this work will describe some of the researches been developed in two important Brazilian Universities: State University of Campinas (UNICAMP) and Federal University of Uberlândia (UFU).
Ciencia and Engenharia/ Science and Engineering Journal, ISSN: 0103944X, Pages: 115-119, Published: 1999