The Experts below are selected from a list of 17976 Experts worldwide ranked by ideXlab platform
S Gangopadhyay - One of the best experts on this subject based on the ideXlab platform.
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performance evaluation of a hard composite solid lubricant coating when dry machining of high carbon steel
Tribology Transactions, 2018Co-Authors: S Gangopadhyay, A K Chattopadhyay, Debajyoti Bhaduri, S PaulAbstract:ABSTRACTA novel hard composite solid lubricant coating combining TiN and MoSx has been developed using pulsed DC closed-field unbalanced magnetron sputtering (CFUBMS). The tribological and mechanical properties together with their interdependencies with the coating microstructures have been assessed and reported elsewhere. This article evaluates the machining performance and correlates the underlying tribological aspects of different TiN-MoSx coating architectures (deposited at titanium (Ti) cathode currents of 1, 3.5, and 5 A) when dry turning AISI 1080 high-carbon steel. A comparative performance study clearly established the supremacy of the composite coating (deposited at 3.5 A Ti cathode current with ∼12 wt% of MoSx) with a hard TiN underlayer over monolayer TiN, MoSx, and other related coating architectures in terms of cutting force, Tool wear, and workpiece surface roughness. The superlubricity behavior of the said composite Coated Tool resulted in a reduction of cutting force (by up to ∼45% compar...
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influence of tribological properties on the performance of unCoated cvd and pvd Coated Tools in machining of incoloy 825
Tribology International, 2016Co-Authors: A Thakur, S GangopadhyayAbstract:Abstract The influence of tribological properties of Coated Tools on performance during machining of nickel-based super alloy is not well reported. The current study comparatively evaluated tribological properties of Tools Coated with chemical vapour deposition (CVD) and physical vapour deposition (PVD) with reference to their unCoated counterpart. The same cutting Tools were then utilised in machining of Incoloy 825. Adhesion, attrition, edge chipping and notch wear were prominent wear mechanism of unCoated followed by CVD Coated Tool. However, PVD Coated Tool outperformed the others. This might be attributed to excellent tribological properties of TiAlN/TiN multilayer coating. Anti-friction and anti-sticking property of TiN and good toughness due to multilayer configuration in combination with thermally resistant TiAlN phase are the primary contributing factors.
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dry machining of nickel based super alloy as a sustainable alternative using tin tialn Coated Tool
Journal of Cleaner Production, 2016Co-Authors: A Thakur, S GangopadhyayAbstract:Abstract Surface coating has been used to improve sustainability in machining process. Therefore, the role of advanced Tool coatings in curtailing the usage of environmentally hazardous cutting fluid (CF) particularly during machining of difficult-to-cut materials needs immediate research attention. In the present work, Incoloy 825, a nickel-based super alloy, has been machined under completely dry environment using a commercially available multilayer (TiN/TiAlN) Coated Tool obtained using physical vapour deposition (PVD). Various machinability characteristics with primarily emphasis on cutting force (responsible for consumed cutting energy), Tool wear (for Tool life) and surface quality (surface roughness) have been compared with those obtained with unCoated Tool under conventional flood cooling and minimum quantity lubrication (MQL). The results achieved under both rough and finish modes of machining clearly established the use of PVD Coated Tool under dry environment as a sustainable strategy for achieving green machining.
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on applicability of multilayer Coated Tool in dry machining of aerospace grade stainless steel
Materials and Manufacturing Processes, 2016Co-Authors: A Mohanty, S Gangopadhyay, A ThakurAbstract:The present research work has been undertaken with a view to investigate the influence of CVD multilayer Coated (TiN/TiCN/Al2O3/ZrCN) and cutting speed on various machining characteristics such as chip morphology, Tool wear, cutting temperature, and machined surface roughness during dry turning of 17-4 PH stainless steel. In order to understand the effectiveness of CVD multilayer Coated Tool a comparison has been carried out with that of unCoated carbide insert. The surface roughness and cutting temperature obtained during machining with chemical vapor deposition (CVD) multilayer Coated Tool was higher than that of unCoated carbide insert at all cutting velocity. However, the results clearly indicated that CVD multilayer Coated Tool played a significant role in restricting various modes of Tool failure and reducing chip deformation compared to its unCoated counterpart. Adhesion and abrasion were found to be dominating wear mechanism with flank wear, plastic deformation, and catastrophic failure being majo...
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comparative evaluation of machinability characteristics of nimonic c 263 using cvd and pvd Coated Tools
Measurement, 2016Co-Authors: B Koyilada, S Gangopadhyay, A ThakurAbstract:Machining of Nimonic C-263 has always been a challenging task owing to its hot strength, low thermal conductivity, tendency to work harden and affinity towards Tool materials. Although Coated Tools have been used to overcome some of these challenges, selection of Coated Tool with appropriate deposition technique is of immense significance. The current study attempts to comparatively evaluate various performance measures in machining of Nimonic C-263 such as surface roughness, cutting force, cutting temperature, chip characteristics, and Tool wear with particular emphasis on different modes of Tool failure for commercially available inserts with multi-component coating deposited using chemical vapour deposition (CVD) and physical vapour deposition (PVD) techniques. Influence of cutting speed (Vc) and machining duration (t) has also been investigated using both Coated Tools. The study demonstrated remarkable decrease in surface roughness (74.3%), cutting force (6.3%), temperature (13.4%) and chip reduction coefficient (22%) with PVD Coated Tool consisting of alternate layers of TiN and TiAlN over its CVD Coated counterpart with TiCN/Al2O3 coating in bilayer configuration. Severe plastic deformation and chipping of cutting edge and nose, abrasive nose and flank wear along with formation of built-up-layer (BUL) were identified as possible mechanisms of Tool failure. PVD Coated Tool successfully restricted different modes of Tool wear for the entire range of cutting speed. Superior performance can be attributed to the hardness and wear resistance properties, thermal stability due to presence of TiAlN phase and excellent toughness owing to PVD technique and multilayer architecture.
A Thakur - One of the best experts on this subject based on the ideXlab platform.
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influence of tribological properties on the performance of unCoated cvd and pvd Coated Tools in machining of incoloy 825
Tribology International, 2016Co-Authors: A Thakur, S GangopadhyayAbstract:Abstract The influence of tribological properties of Coated Tools on performance during machining of nickel-based super alloy is not well reported. The current study comparatively evaluated tribological properties of Tools Coated with chemical vapour deposition (CVD) and physical vapour deposition (PVD) with reference to their unCoated counterpart. The same cutting Tools were then utilised in machining of Incoloy 825. Adhesion, attrition, edge chipping and notch wear were prominent wear mechanism of unCoated followed by CVD Coated Tool. However, PVD Coated Tool outperformed the others. This might be attributed to excellent tribological properties of TiAlN/TiN multilayer coating. Anti-friction and anti-sticking property of TiN and good toughness due to multilayer configuration in combination with thermally resistant TiAlN phase are the primary contributing factors.
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dry machining of nickel based super alloy as a sustainable alternative using tin tialn Coated Tool
Journal of Cleaner Production, 2016Co-Authors: A Thakur, S GangopadhyayAbstract:Abstract Surface coating has been used to improve sustainability in machining process. Therefore, the role of advanced Tool coatings in curtailing the usage of environmentally hazardous cutting fluid (CF) particularly during machining of difficult-to-cut materials needs immediate research attention. In the present work, Incoloy 825, a nickel-based super alloy, has been machined under completely dry environment using a commercially available multilayer (TiN/TiAlN) Coated Tool obtained using physical vapour deposition (PVD). Various machinability characteristics with primarily emphasis on cutting force (responsible for consumed cutting energy), Tool wear (for Tool life) and surface quality (surface roughness) have been compared with those obtained with unCoated Tool under conventional flood cooling and minimum quantity lubrication (MQL). The results achieved under both rough and finish modes of machining clearly established the use of PVD Coated Tool under dry environment as a sustainable strategy for achieving green machining.
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on applicability of multilayer Coated Tool in dry machining of aerospace grade stainless steel
Materials and Manufacturing Processes, 2016Co-Authors: A Mohanty, S Gangopadhyay, A ThakurAbstract:The present research work has been undertaken with a view to investigate the influence of CVD multilayer Coated (TiN/TiCN/Al2O3/ZrCN) and cutting speed on various machining characteristics such as chip morphology, Tool wear, cutting temperature, and machined surface roughness during dry turning of 17-4 PH stainless steel. In order to understand the effectiveness of CVD multilayer Coated Tool a comparison has been carried out with that of unCoated carbide insert. The surface roughness and cutting temperature obtained during machining with chemical vapor deposition (CVD) multilayer Coated Tool was higher than that of unCoated carbide insert at all cutting velocity. However, the results clearly indicated that CVD multilayer Coated Tool played a significant role in restricting various modes of Tool failure and reducing chip deformation compared to its unCoated counterpart. Adhesion and abrasion were found to be dominating wear mechanism with flank wear, plastic deformation, and catastrophic failure being majo...
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comparative evaluation of machinability characteristics of nimonic c 263 using cvd and pvd Coated Tools
Measurement, 2016Co-Authors: B Koyilada, S Gangopadhyay, A ThakurAbstract:Machining of Nimonic C-263 has always been a challenging task owing to its hot strength, low thermal conductivity, tendency to work harden and affinity towards Tool materials. Although Coated Tools have been used to overcome some of these challenges, selection of Coated Tool with appropriate deposition technique is of immense significance. The current study attempts to comparatively evaluate various performance measures in machining of Nimonic C-263 such as surface roughness, cutting force, cutting temperature, chip characteristics, and Tool wear with particular emphasis on different modes of Tool failure for commercially available inserts with multi-component coating deposited using chemical vapour deposition (CVD) and physical vapour deposition (PVD) techniques. Influence of cutting speed (Vc) and machining duration (t) has also been investigated using both Coated Tools. The study demonstrated remarkable decrease in surface roughness (74.3%), cutting force (6.3%), temperature (13.4%) and chip reduction coefficient (22%) with PVD Coated Tool consisting of alternate layers of TiN and TiAlN over its CVD Coated counterpart with TiCN/Al2O3 coating in bilayer configuration. Severe plastic deformation and chipping of cutting edge and nose, abrasive nose and flank wear along with formation of built-up-layer (BUL) were identified as possible mechanisms of Tool failure. PVD Coated Tool successfully restricted different modes of Tool wear for the entire range of cutting speed. Superior performance can be attributed to the hardness and wear resistance properties, thermal stability due to presence of TiAlN phase and excellent toughness owing to PVD technique and multilayer architecture.
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comparative study of surface integrity aspects of incoloy 825 during machining with unCoated and cvd multilayer Coated inserts
Applied Surface Science, 2014Co-Authors: A Thakur, A Mohanty, S GangopadhyayAbstract:Abstract One of the major concerns related to machining of Ni-based super alloy is surface integrity since it directly affects the performance of the machined component during its intended application. In the current study, the influence of cutting speed (51, 84 and 124 m/min) and CVD multilayer Tool coating (TiN/TiCN/Al2O3/ZrCN) on various aspects of surface integrity such as surface roughness, crystal structure and microstructure of the surface and sub-surface region, thickness of white layer and work hardening tendency have been investigated during dry turning of Incoloy 825. Particular emphasis has been given to understand the mechanism of formation of modified surface layer and the associated process of dynamic recrystallization. The study indicated Coated Tool resulted in better surface finish compared to that obtained with unCoated Tool only at high cutting speed. Various macro features of machined surface included feed mark, material smearing, surface ploughing, re-deposited materials and chip debris. Transformation of crystallographic phase of the machined surface could not be detected compared to that of bulk material. Increase in cutting speed caused gradual refinement of grains, and increased white layer thickness. Coated Tool, on the other hand, resulted in the generation of large number of nucleation sites and consequently finer grains at high cutting speed, whereas the unCoated Tool promoted growth of sharply defined recrystallized grains. The Coated Tool prevented the formation of white layer at low and medium cutting speed and also decreased work hardening tendency of Incoloy 825 when compared with that of unCoated Tool.
Rodoula Paraskevopoulou - One of the best experts on this subject based on the ideXlab platform.
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brittleness and fatigue effect of mono and multi layer pvd films on the cutting performance of Coated cemented carbide inserts
Cirp Annals-manufacturing Technology, 2014Co-Authors: G Skordaris, K D Bouzakis, P Charalampous, E Bouzakis, Rodoula ParaskevopoulouAbstract:Abstract The effect of brittleness and fatigue of mono- and multi-layer PVD films on Coated Tools cutting performance is introduced. Cemented carbide inserts were Coated to the same overall film thickness with various numbers of layers. Nanoindentations were conducted to evaluate the hardness of the diverse coating structures. The film brittleness and fatigue were characterized by nano- and macro-impact tests respectively. The Coated inserts’ wear behaviour was investigated in milling hardened steel. The attained results revealed the coatings’ brittleness and fatigue endurance enhancement by increasing the number of film's layers. This increase leads simultaneously to the Coated Tool life improvement.
Zhanqiang Liu - One of the best experts on this subject based on the ideXlab platform.
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influences of coating thickness on cutting temperature for dry hard turning inconel 718 with pvd tialn Coated carbide Tools in initial Tool wear stage
Journal of Manufacturing Processes, 2020Co-Authors: Jinfu Zhao, Zhanqiang LiuAbstract:Abstract High cutting temperatures are induced in the dry cutting process of Inconel 718 for its high hardness 439 HBW and low thermal conductivity 13.4 W/(m K). Due to its thermal barrier effect and antifriction effect, the TiAlN coatings have been deposited on carbide Tools with various coating thicknesses for dry turning Inconel 718. However, the influences of TiAlN coating thickness on cutting temperature of dry turning Inconel 718 were not investigated in details. In this research, PVD TiAlN Tools with coating thickness 1 μm and 2 μm were fabricated and characterized. The cutting temperatures and cutting forces of dry turning Inconel 718 were measured within cutting speed ranges 30−120 m/min. Average friction coefficient at Coated Tool-chip interface was calculated to analyze the coating antifriction effect. Thicker coating induced large temperature increment of 19−30 °C compared with thinner coating within cutting speed ranges of 30−120 m/min in initial Tool wear stage. The results showed that PVD TiAlN Coated Tool with coating thickness 1 μm was more suitable for dry turning Inconel 718 within cutting speed ranges 90−120 m/min by obtaining better coating antifriction effect and lower cutting temperature.
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thermal contact resistance enhancement with aluminum oxide layer generated on tialn Coated Tool and its effect on cutting performance for h13 hardened steel
Surface & Coatings Technology, 2020Co-Authors: Guangchao Hao, Zhanqiang LiuAbstract:Abstract During metal cutting process, thermal contact resistance (TCR) generated at TiAlN-Coated Tool and chip contact interface is enhanced compared with that generated at unCoated Tool and chip interface. However, the TCR enhancement mechanism need to be revealed and its effects on cutting process need to be discussed. In this research, enhancement mechanism of the TCR generated at TiAlN-Coated Tool and chip interface was analyzed by comparing with the TCR formation mechanism of unCoated Tool. Then, effects of the TCR on cutting temperature, cutting forces and Tool life were analyzed. It was found higher nanohardness and elastic modulus of TiAlN-Coated Tool decreased the deformation of rake face asperities. Lower thermal conductivity and greater specific heat of Al2O3 layer resisted cutting heat conducting into Tool. Thermophysical properties of TiAlN coating and generation of Al2O3 oxide layer explained the enhancement mechanism of the TCR. Compared with unCoated Tool, the enhanced TCR of TiAlN-Coated Tool caused more cutting heat to been trapped in chip. Meanwhile, the radial cutting force was reduced by 16.82% and the Tool life was extended by 29.41%. Therefore, the enhanced TCR improved TiAlN-Coated Tool cutting performance when machining H13 hardened steel.
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Influences of TiAlN Coating on Cutting Temperature during Orthogonal Machining H13 Hardened Steel
MDPI AG, 2019Co-Authors: Guangchao Hao, Zhanqiang Liu, Xiaoliang Liang, Jinfu ZhaoAbstract:TiAlN has been widely used in cutting Tool coating due to its excellent mechanical and thermal performances. However, the research on the TiAlN coating effect on cutting temperature is not comprehensive enough. In this paper, the friction tests at elevated temperature and hard machining H13 hardened steel tests are conducted by using TiAlN Coated Tools and unCoated Tools, respectively. The results of using TiAlN Coated Tools are compared with those from using unCoated Tools. It is found that the coefficient of friction (COF) between TiAlN Coated Tool and H13 hardened steel is reduced to 0.63 at 800 °C. The COF value is 0.75 for unCoated Tool. Under the same cutting conditions, the TiAlN coating shortens Tool-chip contact length. The tangential cutting forces and cutting zone temperatures are decreased with smaller COF and shorter Tool-chip contact length. Due to the lower thermal conductivities of TiAlN coating and the Al2O3 oxide layer formatted at Tool rake face, the cutting heat conducted into cutting Tool substrate was reduced. The cutting temperatures in TiAlN Coated Tool substrate are decreased by at least 10.68% in this study. The TiAlN coating reduces the cutting temperature by decreasing the cutting heat generation and conduction
A K Chattopadhyay - One of the best experts on this subject based on the ideXlab platform.
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performance evaluation of a hard composite solid lubricant coating when dry machining of high carbon steel
Tribology Transactions, 2018Co-Authors: S Gangopadhyay, A K Chattopadhyay, Debajyoti Bhaduri, S PaulAbstract:ABSTRACTA novel hard composite solid lubricant coating combining TiN and MoSx has been developed using pulsed DC closed-field unbalanced magnetron sputtering (CFUBMS). The tribological and mechanical properties together with their interdependencies with the coating microstructures have been assessed and reported elsewhere. This article evaluates the machining performance and correlates the underlying tribological aspects of different TiN-MoSx coating architectures (deposited at titanium (Ti) cathode currents of 1, 3.5, and 5 A) when dry turning AISI 1080 high-carbon steel. A comparative performance study clearly established the supremacy of the composite coating (deposited at 3.5 A Ti cathode current with ∼12 wt% of MoSx) with a hard TiN underlayer over monolayer TiN, MoSx, and other related coating architectures in terms of cutting force, Tool wear, and workpiece surface roughness. The superlubricity behavior of the said composite Coated Tool resulted in a reduction of cutting force (by up to ∼45% compar...
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effect of coating thickness on the characteristics and dry machining performance of tin film deposited on cemented carbide inserts using cfubms
Materials and Manufacturing Processes, 2011Co-Authors: Vikas G Sargade, S Gangopadhyay, S Paul, A K ChattopadhyayAbstract:This study deals with the effect of coating thickness on the characteristics and dry machining performance of TiN film deposited on cemented carbide inserts using closed-field unbalanced magnetron sputtering (CFUBMS). The turning inserts were Coated with TiN film of varying thickness ranging from 1.8 µm to 6.7 µm. The deposited coatings were characterized using grazing incidence X-ray diffraction (GIXRD), Vickers and Knoop microhardness tester, and scratch tester. The machining performance of unCoated and Coated carbide inserts was evaluated in dry turning of C40 steel. The in-house developed TiN-Coated carbide insert exhibited around 16 times higher Tool life compared to that of the unCoated insert. Performance test clearly showed the weakness of the unCoated K-type carbide relative to its TiN Coated counterpart in machining of long chipping material like C40 steel. The present investigation clearly reveals that the developed TiN-Coated Tool has a potential for augmenting the cutting capability of uncoat...
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machinability study of pure aluminium and al 12 si alloys against unCoated and Coated carbide inserts
International Journal of Refractory Metals & Hard Materials, 2009Co-Authors: P Roy, S K Sarangi, Amitava Ghosh, A K ChattopadhyayAbstract:Abstract An investigation has been undertaken to study the compatibility of cutting materials in dry machining of aluminium and Al–Si alloys. Mono or multilayer Coated carbide Tools with a top coating of TiC, TiN, TiAlN, Al2O3, TiB2, MoS2 etc. on WC–Co inserts already made a major breakthrough in dry machining of ferrous materials. But in contrast dry machining of aluminium and Al-alloys is a great challenge. But wide application of aluminium different parts has increased the need to find out the correct cutting Tool. Experimental results of turning test, SEM pictures and chip morphology investigation of the cutting Tool after machining clearly reveals the inefficiency of TiC, TiN, TiB2, Al2O3, and AlON in dry machining of aluminium. This is because of the formation of very large amount of metal built-up in both rake and flank surface leading to high magnitude of cutting forces and high roughness of the work-piece during machining. The natural diamond and polycrystalline diamond (PCD) can be used as a cutting Tool, when the required shape is attached on the edge/tip for machining non-ferrous materials. But both of them are limited for finishing cut because of high cost. So CVD diamond Coated Tool is a better option to machine these materials. CVD diamond Coated Tool was free from built-up edge formation leading to clean cut, low magnitude of cutting forces and improved surface finish of the work-piece. However, performances of the diamond Tool depend mainly on adhesion of the diamond coating with the carbide substrate.