New trends in cutting technologies: application of high pressure jet assisted machining (original) (raw)
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Tribology in Industry
High Pressure Jet Assisted Machining (HPJAM) in turning is a hybrid machining method in which a high pressure jet of cooling and lubrication fluid, under high pressure (50 MPa), leads to the zone between the cutting tool edge and workpiece. An experimental study was performed to investigate the capabilities of conventional and high pressure cooling (HPC) in the turning of hard-to-machine materials: hard-chromed and surface hardened steel Ck45 (58 HRc) and hardened bearing steel 100Cr6 (62 HRc). Machining experiments were performed using coated carbide tools and highly cutting speed. Experimental measurements were performed for different input process parameters. The cooling capabilities are compared by monitoring of tool wear, tool life, cooling efficiency, and surface roughness. Connection between the tool wear and surface roughness is established. Experimental research show that the hard turning with carbide cutting tools and HP supply CLF provides numerous advantages from the techno-economic aspect: greater productivity, reduce of temperature in the cutting zone, improved control chip formation, extended tool life, low intensity of tool wear, surface roughness in acceptable limits, significant reduce of production costs related to the CLF.
Transactions of FAMENA, 2016
In this paper, machinability of turned steel defined by monitoring of cutting forces, tool wear, surface quality and chip shape is presented. Experimental investigations were performed on untreated carbon steel C45E (hardness 45 HRc) and on surface induction hardened steel C45E (surface layer hardness 58 HRc). The analysis of machinability was performed under different cooling and lubrication conditions: conventional flooding, minimum quantity lubrication (MQL) and a hybrid machining method, i.e. high pressure jet assisted machining (HPJAM). The investigation was carried out for higher values of processing parameters. The results show the advantages of the advanced cooling and lubricating techniques, i.e. an increase in productivity and a reduction in production costs. The analysis of the results shows that the application of HPJAM gives superior machinability. Beside excellent chip breakability achieved in HPJAM, especially in hardened steel machining, significant improvement in tool life and reduction in cutting forces can be achieved.
Journal of Mechanical Engineering, 2015
Hard turning of harder material differs from conventional turning because of its larger specific cutting forces requirements. The beneficial effects of hard turning can be offset by excessive temperature generation which causes rapid tool wear or premature tool failure if the brittle cutting tools required for hard turning are not used properly. Under these considerations, the concept of high-pressure coolant (HPC) presents itself as a possible solution for high speed machining in achieving slow tool wear while maintaining cutting forces at reasonable levels, if the high pressure cooling parameters can be strategically tuned. This paper deals with an experimental investigation of some aspects of the turning process applied on hardened steel (HRC48) using coated carbide tool under high-pressure coolant, comparing it with dry cut. The results indicate that the use of high-pressure coolant leads to reduced surface roughness, delayed tool flank wear, and lower cutting temperature, while also having a minimal effect on the cutting forces.
Role of High-Pressure Jet Cooling on Cutting Temperature in Turning Steel
The present work deals with development of mathematical model of temperature distribution in chip-tool-work piece interface in turning of medium carbon steel under high-pressure coolant (HPC) condition and subsequently verify it with experimental investigation. Continuous or steady state machining operations like orthogonal cutting are studied by modeling the heat transfer between the tool and chip at the tool rake face contact zone. The shear energy created in the primary zone, the friction energy produced at the rake face-chip contact zone and the heat balance between the moving chip and stationary tool are considered. To determine the temperature distribution in metal cutting is very laborious and time intense through experiment. By using FEM, the temperature distribution in chip-tool-work piece interface can be achieved very accurately. The mathematical model for cutting temperature has been developed and MSC Nastran / Patran simulation software was used to illustrate the temperature distribution. The results were then verified with the experimental data for dry machining. As the results satisfy with acceptable margin, the model then applied for high-pressure coolant condition to find out the temperature distribution in chip-tool-work piece interface. The mathematical models and simulation results are in satisfactory agreement with experimental temperature measurements reported in the literature. In high-pressure coolant condition the average cutting temperature reduced by 16% than dry condition. The model provides reasonably acceptable results in terms of deviation from actual result, with 5% deviation for temperature model. Thus the model proves its validity. As the temperature at the chip-tool interface is one of the two most important factor influencing the machining process, so high-pressure coolant condition is complimentary for machining process.
Influence of Different Cooling and Lubrication Techniques on Material Machinability in Machining
Strojniški vestnik – Journal of Mechanical Engineering, 2013
In this paper, a novel approach to the definition of universal machinability is presented. The machinability model is based on analysing the vector of the cutting process performance. The machinability of C45E steel was analysed and evaluated according to the developed machinability definition. As the machinability criteria, cutting force, intensity of tool wear and surface roughness were used.
Hard turning of bearing steel AISI 52100 with carbide tool and high pressure coolant supply
Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2017
The improvement of productivity, efficiency, and product quality requires the use of modern machining equipment, and modern process management. Successful management of the cutting processes requires a lot of knowledge about workpiece materials, cutting tool materials and geometry, tool machine, cooling and lubrication fluids including dosage techniques, and cutting conditions. However, the mentioned requirements are difficult to achieve in hard turning (Fig. 1). Hard turning is the cutting process for workpiece materials which are hardened above 45 HRc. This method has been introduced to replace traditional processes, which included turning, heat treatment and grinding [1]. Hard turning is almost performed using harder cutting tool materials such are the ceramics (Al 2 O 3) and cubic boron nitride tools (CBN), at lower cutting parameter values. The use of these tools and parameters causes expensive production, because of expensive tools and long machining time. The use of brittle tools requires continuous cut due to poor toughness of cutting tool edges. Use of cooling and lubrication fluid supplied under high pressure can bring some improvements in machining. This technique of fluid supplying dates from the fifties of the last century. In modern machining are used the high pressure tool systems that allow the fluid supply under pressures up to 15 MPa. The high pressure jet assisted machining (HPJAM) concept is to inject an extremely high pressure jet of cooling and lubrication fluid in the cutting zone, between chip and tool edge. In this techniques are used pressures from 40 to 200 MPa, so that jet is participating in the chips forming, similar to the non-conventional technologies [2-4]. HPJAM was established as a method that would substantially increase the removal rate and Abstract The machining of hard-to-machine bearing steel AISI 52100 (100Cr6), hardened to 62 HRc, is almost impossible using standard machining conditions and carbide cutting tools. The purpose of this research is machinability analysis and conclusions about the conditions that allow the machining of mentioned steel with carbide tools. In this paper, the turning process is carried out using coated carbide inserts and high pressure jet assisted machining, as a special technique of cooling and lubrication. In this technique, coolant circulation system with filters, environmentally acceptable, is used. A jet of cooling and lubrication fluid under extremely high pressure (50 MPa) is directed into the zone between the cutting tool edge and the workpiece. Experimental measurements were performed for different cutting parameters. Cutting forces, tool wear, surface roughness, chip shapes, and material removal rates were analyzed. The presented results show an increase in productivity, low intensity tool wear, and surface roughness in acceptable limits.
International Journal of Machine Tools and Manufacture, 2009
This study aims at investigating the effects of high-pressure jet assistance (HPJA) in rough turning of Inconel 718. A finite element (FE) model for orthogonal machining has been developed in order to reach additional data, compare trends to the experimental ones and understand the influence of the jet on the cutting process. Mechanical and thermal loads induced by the jet are considered. Consequences on the primary and secondary shear zones, chip formation and tool rake face have been studied on a whole pressure range (30-130 MPa) and compared to dry cutting. It is shown that the jet is able to decrease the cutting forces, chip radius and tool-chip contact length. Contact pressure and temperature fields on the cutting tool are also reduced as well as the sticking part of the contact zone. Authors confirmed that the effects of convection are able to change and even amplify the influence of the pure mechanical load induced by the jet.
Optimization of Turning Process Parameters in Machining Heat Treated Steel
International Journal for Research in Applied Science and Engineering Technology IJRASET, 2020
The present experimental approach on turning studies the process parameters that are affecting the machining performance and productivity of Plain Turning. The design of experiments is based on Taguchi's L9 orthogonal array. The response table and response graph for each level of machining parameters are obtained from Taguchi method to select the optimal levels of machining parameters. In the present work, the machining parameters are Speed, Feed Rate and Depth of Cut, which are optimized for maximum material removal rate (MRR) and minimum Surface Roughness during turning of Heat Treated Steel (EN-9). I. INTRODUCTION Today competitive market demands efficient manufacturing with high quality, optimum manufacturing cost and environmental sustainability consideration. This is achieved by advanced engineering materials and automated machining. New industrial applications require materials with advanced properties for products particular requirements with reliable and economical manufacturing processes and higher productivity. These advanced engineering materials are used in automotive, aerospace, electronics, medical applications and others industries. The advanced and modified properties will improve the quality of these materials and help meet certain mechanical, electrical, or chemical requirements. Typical properties that are needed are tensile strength, hardness, thermal conductivity, and corrosion and wear resistance. Studies have been performed by various researchers in the domain of plain turning. The researchers have performed analysis for providing knowledge of current plain turning trend. S.R. Das et al [1] conducted experiments on Tungsten AISI 4340 steel with Coated Graphite tool inserts. Feed was found to be most significant parameter for the workpiece surface roughness (Ra) with a percent contribution of 52.55%. Cutting speed was found to be the next significant parameter for Ra with contribution of 25.85%. Depth of cut was found a negligible influence in case of Ra. Jitendra. M. Varma et al [2] conducted experiments on AISI 4340 using solid lubricant with coated carbon tool inserts. It is concluded that the application of solid lubricant in dry machining has proved to be a feasible alternative to cutting fluid, if it can be applied properly. There is a considerable improvement in surface roughness and quality of product produced. Karanam Krishna et al [3] carried an investigation using ANN for material removal rate on Aluminum in turning. This work investigated the influence of the operating parameters like feed rate, depth of cut, clamping length and spindle speed. It was evident that each of these parameters studied contributed to the error in the dimensions of the machined component. Depth of cut and the feed rate had more effect on the accuracy than the other parameters. Based on this ANN prediction, the NC program could be corrected before commencing the actual machining operation, thus improving the accuracy of the component at less cost and time. A.Sathyavathi et al [4] carried a study on different researches conducted. The most of researchers are interested in optimization of machining condition with corresponding surface roughness. In past reviewed found, none of researcher involved for TiBN coated cemented carbide tool. In this paper uncoated carbide tool and PVD (TiBN) coated carbide tool involved for performance of quality of surface and optimization of cutting parameter with aid of DOE and GA. M.M.A. Khan et al [5] carried an investigation to analyze the effects of minimum quantity lubrication on turning AISI 9310 alloy steel using vegetable oil-based cutting fluid. They concluded that the chips produced under both dry and wet condition are of ribbon type continuous chips at lower feed rates and more or less tubular type continuous chips at higher feed rates. The significant contribution of MQL jet in machining the low alloy steel by the carbide insert undertaken has been the reduction in flank wear, which would enable either remarkable improvement in tool life or enhancement of productivity (MRR) allowing higher cutting velocity and feed. The Surface finishes also improved mainly due to reduction of wear and damage at the tool-tip by the application of MQL.
The machinability of nickel-based alloys in high-pressure jet assisted (HPJA) turning
Metalurgija, 2013
Due to their mechanical, thermal and chemical properties, nickel-based alloys are generally included among materials that are hard to machine. An experimental study has been performed to investigate the capabilities of conventional and high-pressure jet assisted (HPJA) turning of hard-to-machine materials, namely Inconel 718. The capabilities of different hard turning procedures are compared by means of chip breakability. The obtained results show that HPJA method offers a significant increase in chip breakability, under the same cutting conditions (cutting speed, feed rate, depth of cut).
International Journal of Machine Tools and Manufacture, 2011
This study deals with the effect of High-Pressure Water Jet Assisted Turning (HPWJAT) of austenitic stainless steels on chip shape and residual stresses. The machining of the austenitic stainless steels represents several difficulties. Recently, research has shown that the introduction of a high-pressure water jet into the gap between the tool and the chip interface is a very satisfactory method for machining applications. In this article, the effect of a high-pressure water jet, directed into the toolchip interface, on chip shapes breakage and surface integrity in face turning operations of AISI 316L steel has been investigated. Tests have been carried out with a standard cutting tool. The cutting speeds used were 80 and 150 m/min, with a constant feed rate of 0.1 mm/rev and a constant cutting depth of 1 mm. Three jet pressures were used: 20, 50 and 80 MPa. Residual stress profiles have been analysed using the X-ray diffraction method in both longitudinal and transversal directions. The results show that jet pressure and cutting parameters influence the residual stresses and the chip shapes.