The Experts below are selected from a list of 10797 Experts worldwide ranked by ideXlab platform
I S Jawahir - One of the best experts on this subject based on the ideXlab platform.
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minimising carbon emissions and machining costs with improved human health in sustainable machining of austenitic stainless steel through multi objective optimisation
International Journal of Shape Modeling, 2020Co-Authors: Alper Uysal, J Caudill, Julius Schoop, I S JawahirAbstract:Environmental and societal concerns have fuelled an ever growing need for more sustainable products and machining processes. Much research has been focused on this issue in aviation, automotive, and medical industries where austenitic stainless steels have been often used. During machining of these materials, high cutting forces and carbon emissions make the machining process significantly more challenging. Therefore, in this study sustainable orthogonal turning experiments were conducted using dry cutting, MQL, and Cryogenic Cooling at different cutting speeds and undeformed chip thicknesses. Experimental cutting forces were measured and used to analytically determine the carbon (CO2) emissions. In order to determine the optimal machining parameters for minimising the CO2 emissions and the overall economic cost with improved human health conditions, a multi-objective optimisation problem was established. The optimal machining parameters were determined to be a cutting speed of 100 m/min and undeformed chip thickness of 0.12 mm, while using Cryogenic Cooling.
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high speed Cryogenic finish machining of ti 6al4v with polycrystalline diamond tools
Journal of Materials Processing Technology, 2017Co-Authors: Julius Schoop, Wisley Falco Sales, I S JawahirAbstract: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.
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Cryogenic Cooling induced process performance and surface integrity in drilling cfrp composite material
The International Journal of Advanced Manufacturing Technology, 2016Co-Authors: T Xia, Yusuf Kaynak, C Arvin, I S JawahirAbstract:Therehasbeenasubstantialgrowthinusingcarbon fiber-reinforced plastic (CFRP) composite materials in aero- space and automotive industries due to their superior proper- ties. This experimental study presents results from a compre- hensive and systematic study investigating the effects of cryo- genic Cooling on drilling performance and surface integrity characteristics of CFRP composite material. Experimental da- ta on cutting edge radius of drill bit, outer corner wear of drill bit, trust force, torque, delamination factor, and surface integ- ritycharacteristics,includingboreholesubsurfacedamageand diameter error of drilled hole, are presented and analyzed comparing dry drilling with Cryogenic Cooling of CFRP com- posite material. The findings demonstrate that Cryogenic Cooling has a profound effect on reducing the cutting edge rounding of drill bit and outer corner wear; it also helps en- hancing the surface integrity characteristics of produced hole. However, Cryogenic Cooling generates larger thrust force, torque, and thus larger delamination factor.
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The effects of Cooling conditions on surface integrity in machining of Ti6Al4V alloy
The International Journal of Advanced Manufacturing Technology, 2014Co-Authors: G. Rotella, Domenico Umbrello, O. W. Dillon, L. Settineri, I S JawahirAbstract:This paper presents results from a comparative study of machining of Ti6Al4V alloy under dry, minimal quality lubrication, and Cryogenic Cooling conditions using coated tools at varying cutting speeds and feed rates. The influence of the Cooling conditions on surface integrity and the product performance was studied in terms of surface roughness, metallurgical conditions, including microstructure, hardness, grain refinement, and phase transformation of the machined product. Results show that Cooling conditions affect surface integrity of the product signifying the benefits of Cryogenic Cooling in improving the overall product performance.
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tool wear analysis in Cryogenic machining of niti shape memory alloys a comparison of tool wear performance with dry and mql machining
Wear, 2013Co-Authors: Yusuf Kaynak, H E Karaca, Ronald D Noebe, I S JawahirAbstract:Abstract Extremely high tool-wear rate in machining of NiTi shape memory alloys (SMAs) is one of the major reasons for limiting the use of conventional machining processes on NiTi. The present study begins to address this issue by examining the effects of Cryogenic Cooling on tool-wear rate and progressive tool-wear by comparing the new findings from Cryogenic machining with results obtained from minimum quantity lubrication (MQL) and dry machining conditions. Flank wear at the nose region, notch wear at the depth of cut boundary, and resulting machining performance criteria such as force components and surface quality of machined samples were studied. The findings from this research demonstrate that Cryogenic Cooling has a profound effect on controlling tool-wear rate and that the progressive tool-wear in machining of NiTi shape memory alloys can be significantly reduced by Cryogenic machining.
A B Chattopadhyay - One of the best experts on this subject based on the ideXlab platform.
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machining of aisi 4140 steel under Cryogenic Cooling tool wear surface roughness and dimensional deviation
Journal of Materials Processing Technology, 2002Co-Authors: Nikhil Ranjan Dhar, S Paul, A B ChattopadhyayAbstract:Abstract Increase in cutting velocity and feed for machining with high productivity is generally restricted by the elevated cutting temperature which causes rapid tool failure. In precision machining also, the major problem is the high cutting temperature, which impairs the dimensional and form accuracy of the product, its surface integrity by inducing tensile residual stresses and surface and subsurface cracks. Application of conventional cutting fluid often cannot control the high cutting temperature in high production machining. Besides, they are the major source of pollution from machining industries. Cryogenic Cooling is an environment friendly clean technology for desirable control of cutting temperature. The present work investigates the role of Cryogenic Cooling by liquid nitrogen jet on average chip–tool interface temperature, tool wear, dimensional accuracy and surface finish in turning AISI 4140 steel under industrial speed–feed conditions.
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role of Cryogenic Cooling on cutting temperature in turning steel
Journal of Manufacturing Science and Engineering-transactions of The Asme, 2002Co-Authors: Nikhil Ranjan Dhar, S Paul, A B ChattopadhyayAbstract:Application of conventional cutting fluids do not serve the purposes effectively particularly under high cutting velocity and feed. Besides, such cutting fluids pollute the environment in high production machining and grinding. Cryogenic Cooling seemed to be quite effective in reducing the high cutting temperature which impairs product quality and reduces tool life. The present work deals with investigating the role of Cryogenic Cooling by liquid nitrogen jet on cutting temperature in turning plain carbon steel (C-40) under varying cutting velocity and feed. The experimental and computational results indicate that such Cryogenic Cooling enables substantial reduction in the cutting temperature depending upon the levels of the cutting velocity and feed and the cutting tool geometry. It was also noted that the chip formation and chip-tool interaction become more favorable and the cutting forces decreased to some extent when liquid nitrogen jet was employed. Therefore, it appears that Cryogenic Cooling, if properly employed, not only provides environment friendliness but can also improve the machinability characteristics.
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the influence of Cryogenic Cooling on tool wear dimensional accuracy and surface finish in turning aisi 1040 and e4340c steels
Wear, 2001Co-Authors: Nikhil Ranjan Dhar, S Paul, A B ChattopadhyayAbstract:Abstract In all machining operations, tool wear is a natural phenomenon and it eventually leads to tool failure. The growing demands for high productivity of machining need use of high cutting velocity and feed rate. Such machining inherently produces high cutting temperature, which not only reduces tool life but also impairs the product quality particularly when the work piece is quite strong, hard and heat resistant. Conventional Cooling methods are not only ineffective but also deteriorate the working environment by producing harmful gasses and smokes. Attempts have already been initiated to control the pollution problem by Cryogenic Cooling which also enables get rid of recycling and disposal of conventional fluids and possible damage of the machine parts by corrosion, etc. This paper deals with experimental investigation on the role of Cryogenic Cooling by liquid nitrogen jet on tool wear and product quality in plain turning of AISI 1040 and E4340C steel at industrial speed–feed combinations by two types of carbide inserts of different geometry. The encouraging results include significant reduction in tool wear rate, dimensional inaccuracy and surface roughness by Cryogenic Cooling application mainly through reduction in the cutting zone temperature and favourable change in the chip–tool and work–tool interaction.
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beneficial effects of Cryogenic Cooling over dry and wet machining on tool wear and surface finish in turning aisi 1060 steel
Journal of Materials Processing Technology, 2001Co-Authors: S Paul, A B ChattopadhyayAbstract:Abstract High production machining of steel inherently generate high cutting temperature, which not only reduces tool life but also impairs the product quality. Conventional cutting fluids are ineffective in controlling the high cutting temperature and rapid tool wear. Further, they also deteriorate the working environment and lead to general environmental pollution. Attempts have already been initiated to control the pollution problem by Cryogenic Cooling which helps also in getting rid of recycling and disposal of conventional fluids. The present work deals with experimental investigation in the role of Cryogenic Cooling by liquid nitrogen jet on tool wear and surface finish in plain turning of AISI 1060 steel at industrial speed-feed combination by two types of carbide inserts of different geometric configurations. The results have been compared with dry machining and machining with soluble oil as coolant. The results of the present work indicate substantial benefit of Cryogenic Cooling on tool life and surface finish. This may be attributed to mainly reduction in cutting zone temperature and favorable change in the chip–tool interaction. Further, it was evident that machining with soluble oil Cooling failed to provide any significant improvement in tool life, rather surface finish deteriorated.
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effects of Cryogenic Cooling by liquid nitrogen jet on forces temperature and surface residual stresses in grinding steels
Cryogenics, 1995Co-Authors: S Paul, A B ChattopadhyayAbstract:Grinding is a widely employed finishing process for different materials such as metals, ceramics, glass, carbides, rocks, etc. to achieve good geometrical (form) and dimensional accuracy with acceptable surface finish and surface integrity. However, it is inherently characterized by high specific energy requirements, unlike other conventional machining processes such as turning, milling, etc., which lead to a high grinding zone temperature and poor surface integrity. Many methods have been investigated to control this high grinding zone temperature, but all have their shortfalls, both technological and environmental, in exchange for controlling the grinding zone temperature. This paper briefly discusses the results obtained with regard to grinding forces, specific energy, grinding zone temperature and surface residual stress when using Cryogenic Cooling and compares them to the results from dry grinding and grinding with soluble oil. Cryogenic Cooling seems to have the edge over other coolants in terms of controlling the temperature, residual stresses and grinding forces, and it is also environment friendly.
Domenico Umbrello - One of the best experts on this subject based on the ideXlab platform.
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The effects of Cooling conditions on surface integrity in machining of Ti6Al4V alloy
The International Journal of Advanced Manufacturing Technology, 2014Co-Authors: G. Rotella, Domenico Umbrello, O. W. Dillon, L. Settineri, I S JawahirAbstract:This paper presents results from a comparative study of machining of Ti6Al4V alloy under dry, minimal quality lubrication, and Cryogenic Cooling conditions using coated tools at varying cutting speeds and feed rates. The influence of the Cooling conditions on surface integrity and the product performance was studied in terms of surface roughness, metallurgical conditions, including microstructure, hardness, grain refinement, and phase transformation of the machined product. Results show that Cooling conditions affect surface integrity of the product signifying the benefits of Cryogenic Cooling in improving the overall product performance.
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analysis of the white layers formed during machining of hardened aisi 52100 steel under dry and Cryogenic Cooling conditions
The International Journal of Advanced Manufacturing Technology, 2013Co-Authors: Domenico UmbrelloAbstract:The present work aims at understanding the effects of Cryogenic coolant application and machined surface alterations during orthogonal machining of hardened AISI 52100 bearing steel. Experiments were performed under dry and Cryogenic Cooling conditions using cubic boron nitride tool inserts with varying initial hardness and tool shape. Several experimental techniques were used in order to analyze the machined surface. In particular, optical and scanning electron microscopes were used for characterizing the surface topography, whereas the microstructural phase composition analysis and chemical characterization have been performed by means of X-ray diffraction and energy-dispersive spectroscopy techniques. The experimental results prove that the white layer is partially reduced or can be totally eliminated under certain process parameters and Cryogenic Cooling condition.
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the effects of Cryogenic Cooling on surface integrity in hard machining a comparison with dry machining
Cirp Annals-manufacturing Technology, 2012Co-Authors: Domenico Umbrello, F Micari, I S JawahirAbstract:Abstract This paper presents results of an experimental study of Cryogenic machining of hardened AISI 52100 steel, focusing on surface integrity. Experiments were performed under dry and Cryogenic Cooling conditions using CBN tools varying cutting speeds, workpiece hardness and tool geometry. Surface integrity parameters (surface roughness, white layer thickness, residual stresses, metallurgical conditions including grain size, phase transformation, etc.) were investigated to establish the effects of Cryogenic Cooling on the surface integrity of the machined component, and results were compared with those from dry hard machining. Overall, Cryogenic Cooling provides improved surface integrity leading to extended product life and performance.
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the effects of Cryogenic Cooling on surface integrity in hard machining
Procedia Engineering, 2011Co-Authors: Domenico Umbrello, Jose Outeiro, A D Jayal, O. W. Dillon, Serafino Caruso, I S JawahirAbstract:Abstract This paper presents the results of an experimental investigation to determine the effects of Cryogenic coolant on surface integrity in orthogonal machining of hardened AISI 52100 bearing steel. Experiments were performed under dry and Cryogenic conditions using chamfered CBN tool inserts. Several experimental techniques were used in the analyzing of the machined surface and subsurface: optical and scanning electron microscopes (SEM) were utilized for the surface topography characterization; chemical characterization (phase study) was carried out by means of Energy-dispersive spectroscopy (EDS) techniques; and X-ray diffraction (XRD) technique was used to determine residual stresses and phase changes induced by dry and Cryogenic machining. The results show the benefits and the future potential of Cryogenic Cooling for surface integrity enhancement to achieve improved product's functional performance in hard machining.
Stephen T. Newman - One of the best experts on this subject based on the ideXlab platform.
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comparative investigation on using Cryogenic machining in cnc milling of ti 6al 4v titanium alloy
Machining Science and Technology, 2016Co-Authors: Alborz Shokrani, Vimal Dhokia, Stephen T. NewmanAbstract:ABSTRACTTi-6Al-4V titanium alloy is one of the most important materials in industry, 80% of which is used in aerospace industry. Titanium alloys are also notoriously difficult-to-machine materials owing to their unique material properties imposing a major bottleneck in manufacturing systems. Cryogenic Cooling has been acknowledged as an alternative technique in machining to improve the machinability of different materials. Although milling is considered to be the major machining operation for the manufacture of titanium components in aerospace industries, studies in Cryogenic machining of titanium alloys are predominantly concentrated on turning operations. To address this gap, this article provides an investigation on the viability of Cryogenic Cooling in CNC end-milling of aerospace-grade Ti-6Al-4V alloy using liquid nitrogen in comparison with traditional machining environments. A series of machining experiments were conducted and surface roughness, tool life, power consumption, and specific machining ...
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Investigation of the effects of Cryogenic machining on surface integrity in CNC end milling of Ti-6Al-4V titanium alloy
Journal of Manufacturing Processes, 2016Co-Authors: Alborz Shokrani, Vimal Dhokia, Stephen T. NewmanAbstract:This paper presents the first comprehensive investigation on the effects of Cryogenic Cooling using liquid nitrogen on surface integrity of Ti-6Al-4V titanium alloy workpiece in end milling operations. Titanium is classified as a notoriously difficult-to-machine material, where its machining is characterised by poor surface integrity and short tool life. Increasing productivity, whilst meeting surface integrity requirements for aerospace and medical titanium-based components has always been a challenge in machining operations. Cryogenic machining using super cold liquid nitrogen at -197 °C is a method to facilitate heat dissipation from the cutting zone and reduce the chemical affinity of workpiece and cutting tool materials and therefore improving machinability. Since milling is one of the major machining operations for aerospace components, this study is concentrated on Cryogenic milling. The effects of Cryogenic Cooling on surface integrity are compared to conventional dry and flood Cooling in end milling Ti-6Al-4V titanium alloy. A series of machining experiments were conducted at various combinations of cutting parameters. Surface roughness and microscopic surface integrity were investigated and subsurface microhardness was measured for each sample. The analysis indicated that Cryogenic Cooling has resulted in up to 39% and 31% lower surface roughness when compared to dry and flood Cooling methods, respectively. Furthermore, microscopic surface defects were significantly reduced as a result of Cryogenic. The investigations indicated that Cryogenic Cooling considerably improves surface integrity in end milling of Ti-6Al-4V.
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an initial study of the effect of using liquid nitrogen coolant on the surface roughness of inconel 718 nickel based alloy in cnc milling
Procedia CIRP, 2012Co-Authors: Vimal Dhokia, Stephen T. Newman, R ImaniasraiAbstract:The most used alloy of nickel, Inconel 718 is known to difficult to machine owing to its superior material and physical properties. This paper presents one of the very first studies on Cryogenic CNC end milling of the Inconel 718 nickel based alloy using TiAlN coated solid carbide tools. The experimental investigations revealed that Cryogenic Cooling has a significant potential to improve surface roughness of machined parts as compared to dry machining without noticeable increase in power consumption of the machine tool. In addition to surface roughness, power consumption and tool wear have also been monitored in this study.
Muammer Nalbant - One of the best experts on this subject based on the ideXlab platform.
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effect of Cryogenic Cooling in milling process of aisi 304 stainless steel
Transactions of Nonferrous Metals Society of China, 2011Co-Authors: Muammer Nalbant, Yakup YildizAbstract:The effects of Cryogenic Cooling on cutting forces in the milling process of AISI 304 stainless steel were investigated experimentally. Cryogenic Cooling was achieved by spraying liquid nitrogen to tool, chips and material interfaces using a pipe with an internal diameter of 1 mm; the flow rate of liquid nitrogen was 5.2 L/min; two cutting directions (climbing and conventional milling), two machining conditions (dry and Cryogenic Cooling) and four cutting speeds (80, 120, 160 and 200 m/min) were used in the milling process. Cryogenic Cooling and cutting speed are found to be effective on cutting forces. Cutting forces and torque in Cryogenic milling are higher than those in dry milling. Cutting force is increased as the cutting speed is increased. Tool fritter around insert nose radius is the main problem of climb milling method in Cryogenic Cooling at low cutting speeds.
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a review of Cryogenic Cooling in machining processes
International Journal of Machine Tools & Manufacture, 2008Co-Authors: Yakup Yildiz, Muammer NalbantAbstract:The Cooling applications in machining operations play a very important role and many operations cannot be carried out efficiently without Cooling. Application of a coolant in a cutting process can increase tool life and dimensional accuracy, decrease cutting temperatures, surface roughness and the amount of power consumed in a metal cutting process and thus improve the productivity. In this review, liquid nitrogen, as a Cryogenic coolant, was investigated in detail in terms of application methods in material removal operations and its effects on cutting tool and workpiece material properties, cutting temperature, tool wear/life, surface roughness and dimensional deviation, friction and cutting forces. As a result, Cryogenic Cooling has been determined as one of the most favourable method for material cutting operations due to being capable of considerable improvement in tool life and surface finish through reduction in tool wear through control of machining temperature desirably at the cutting zone.