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A comparative study on the tribological behavior of mono&proportional hybrid nanofluids for sustainable turning of AISI 420 hardened steel with cermet tools
(Elsevier Sci Ltd, 2022) Yildirim, Cagri Vakkas; Sirin, Senol; Kivak, Turgay; Sarikaya, Murat
The current study examines the influence of various mono and proportional hybrid nanofluids prepared with multi-walled carbon nanotube (MWCNT), alumina (Al2O3) and molybdenum disulphide (MoS2) on the performance of cermet tools in turning of AISI 420 hardened steel. First, mono-nanofluids were prepared using each nanoparticle separately (i.e., Al2O3, MWCNT and MoS2). Afterward, hybrid nanofluids were prepared at three different nanoparticle mixture ratios i.e., particle A:particle B of 1:1 (50 vol% + 50 vol%), particle A:particle B of 1:2 (33.34 vol% + 66.66 vol%), particle A:particle B of 2:1 (66.66 vol% + 33.34 vol%) in a constant volume concentration of 0.6%. Prepared nanofluids (nine different hybrid nanofluids and three different mono nanofluids) were cooperated with the MQL system and their effects on the machinability characteristics such as surface roughness, surface topography, temperature, tool flank wear, and wear mechanisms were investigated. The results were compared with dry and base-fluid MQL assisted cutting results. The surface roughness was decreased by 41.54%, 37.38% and 30.62% through Al2O3:MoS2 (2:1), Al2O3:MoS2 (1:2) and Al2O3:MoS2 (1:1) hybrid nanofluids compared to base fluid, respectively. It was found that different ratios of one more than nanoparticles have a significant effect on the synergistic effect. Based on the all experimental results, it can be concluded that it is necessary to optimize the nanoparticle ratios used in the preparation of hybrid nanofluids.
A state-of-the-art review on tool wear and surface integrity characteristics in machining of superalloys
(Elsevier, 2021) Sarikaya, Murat; Gupta, Munish Kumar; Tomaz, Italo; Pimenov, Danil Yu; Kuntoglu, Mustafa; Khanna, Navneet; Yildirim, Cagri Vakkas
Today, superalloys (also known as hard-to-cut materials) such as nickel, titanium and cobalt based cover a wide range of areas in engineering applications. At the same time, challenging material properties namely high strength and low thermal conductivity cause low quality in terms of cutting tool life and surface integrity of the machined part. It is important to improve the machinability of this type of materials by applying various methods in the perspective of sustainability. Therefore, current study presents surface integrity, tool wear characteristics and initiatives to improve them during the machining of superalloys. In this manner, it is outlined the surface integrity characteristics containing surface defects, surface roughness, microstructure alterations and mechanical properties. Also, tool wear mechanisms for example abrasive, adhesive, oxidation, diffusion and plastic deformation are investigated in the light of literature review. Finally, possible improvement options for tool wear and surface integrity depend on machining parameters, tool modifications, cooling methods and trade-off strategies are highlighted. The paper can be a guide for the researchers and manufacturers in the area of sustainable machining of hard-to-cut materials as explaining the latest trends and requirements. (C) 2021 CIRP.
An attempt towards green machining of Ni-based Hastelloy C4 alloy: Effect of vegetable oils and their combination with TiO2 and SiO2 nanoparticles on outputs
(Elsevier, 2023) Yildirim, Cagri Vakkas; Sirin, Senol; Kivak, Turgay; Ercan, Hamdi; Sarikaya, Murat
The importance of nickel-based superalloys has increased day by day due to their use in special applications. However, the difficulties in the machinability of these alloys bring some concerns about parts quality and efficiency. Although researchers have tried ways (such as the use of high-performance cutting fluids) to overcome these challenges, their sustainability is still controversial. Therefore, this experimental research aims to contribute to the sustainable machining of nickel-based superalloys. In this regard, the present study investigates the effectiveness of vegetable-based fluids (sunflower, olive, hazelnut, and corn oils) and nanofluids (SiO2 + sunflower oil, SiO2 + olive oil, SiO2 + hazelnut oil, SiO2 + corn oil, TiO2 + sunflower oil, TiO2 + olive oil, TiO2 + hazelnut oil, and TiO2 + corn oil) during the machining of Ni-based Hastelloy C4 alloy. The study was carried out in three stages. In the first stage, all cutting fluids' pH and thermal conductivity values were measured. In the second stage, machinability tests were conducted under the prepared cutting fluids. Later, friction-wear tests of the cutting fluids that offered the best performance in the previous stage were done. As a result, the pH change was significantly increased with the addition of nanoparticles (TiO2 and SiO2) to corn oil. TiO2 nanoparticles allowed further improvement of thermal conductivity. Compared to dry machining, improvements of 58.57%, 34.88%, 53.18%, and 36.1% in surface roughness, cutting temperature, tool wear, and power consumption were achieved with corn oil+TiO2 nanofluid, respectively. It was determined that adhesion, BUE, BUL, and chipping were dominant damage types. Also, an adhesive is the dominant wear mechanism.
Comprehensive analysis of cutting temperature, tool wear, surface integrity and tribological properties in sustainable milling of Ti6Al4V alloy: LN2, nanofluid and hybrid machining
(Elsevier Sci Ltd, 2024) Sirin, Emine; Yildirim, Cagri Vakkas; Sirin, Senol; Kivak, Turgay; Sarikaya, Murat
Despite being expensive and difficult to process, the Ti6Al4V alloy is a vital component for crucial industries. To improve its machinability and accomplish sustainable production, environmentally friendly cooling and lubricating agencies are used. Studies on the machinability of the alloy are still necessary because of its unique features and significance in vital industries like aerospace, defense, and medicine. Therefore, this investigation focuses on tool wear, temperature, and surface integrity for sustainable milling Ti6Al4V under various machining environments, i.e., dry, pure-MQL, LN2, 2 , hBN, CuO-doped nanofluids, and hybrid methods. The produced nanofluids' thermophysical and rheological characteristics were examined in the study's initial phase. Because of the results from the first stage, machining performance indicators were assessed in the subsequent milling experiments. As a result, CuO-doped nanofluids gave improved results in terms of viscosity and pH. The best results obtained in the LN2 2 + CuO hybrid cooling lubrication environment in important machinability outcomes such as tool wear and surface integrity were attributed to the rheological properties of CuO-doped nanofluid and its harmonious cooperation with LN2-cryogenic 2-cryogenic cooling.
Determination of MQL Parameters Contributing to Sustainable Machining in the Milling of Nickel-Base Superalloy Waspaloy
(Springer Heidelberg, 2017) Yildirim, Cagri Vakkas; Kivak, Turgay; Sarikaya, Murat; Erzincanli, Fehmi
In addition to reducing production costs, minimum quantity lubrication (MQL) aims to minimize the adverse effects of conventional cutting fluid usage on the environment and human health. Because of the positive effect of the MQL system on both health and production efficiency, sustainable production is increasing daily. Therefore, optimum MQL parameters must be determined in order to obtain maximum efficiency in the manufacturing process. In this study, unlike similar studies in which MQL parameters were evaluated, the scope was widened and the main parameters affecting the efficiency of the system were tested at the same time. For this aim, nickel-base superalloy Waspaloy was machined under MQL using a CNC milling machine with uncoated carbide inserts. In the machining process, the MQL parameters selected were cutting oil type (mineral-, synthetic-, mineral-synthetic-and vegetable-based oils), fluid flow rate (25, 50, 75 and 100 ml/h), milling method (up milling and down milling), spray distance (25 and 50 mm) and nozzle type (Type 1 and Type 2). In order to analyze the effect of MQL parameters on the quality characteristics of tool life and cutting force, the cutting parameters, including cutting speed, feed rate and depth of cut, were kept constant for all experiments. Taguchi's L16 (4(2) x 2(3)) orthogonal array was employed to minimize the number of experiments. As a result, both maximum tool life and minimum cutting force were attained via a combination of vegetable-based cutting oil, 100 ml/h flow rate, opposite-direction (up) milling, Type 1 nozzle and a 25-mm spray distance.
Evaluation of tool wear, surface roughness/topography and chip morphology when machining of Ni-based alloy 625 under MQL, cryogenic cooling and CryoMQL
(Elsevier, 2020) Yildirim, Cagri Vakkas; Kivak, Turgay; Sarikaya, Murat; Sirin, Senol
Although nickel-based aerospace superalloys such as alloy 625 have superior properties including high-tensile and fatigue strength, corrosion resistance and good weldability, etc., its machinability is a difficult task which can be solved with alternative cooling/lubrication strategies. It is also important that these solution methods are sustainable. In order to facilitate the machinability of alloy 625 with sustainable techniques, we investigated the effect of minimum quantity lubrication (MQL), cryogenic cooling with liquid nitrogen (LN2) and hybrid-CryoMQL methods on tool wear behavior, cutting temperature, surface roughness/topography and chip morphology in a turning operation. The experiments were performed at three cutting speeds (50, 75 and 100 mirnin), fixed cutting depth (0.5 mm) and feed rate (0.12 mm/rev). As a result, CryoMQL improved surface roughness (1.42 mu m) by 24.82% compared to cryogenic cooling. The medium level of cutting speed (75 mirnin) can be preferred for the lowest roughness value and lowest peak-to-valley height when turning of alloy 625. Further, tool wear is decreased by 50.67% and 79.60% by the use of MQL and CryoMQL compared with cryogenic machining. An interesting result that MQL is more effective than cryogenic machining in reducing cutting tool wear. (C) 2019 The Authors. Published by Elsevier B.V.
Experimental investigation on the effect of dry and multi-jet cryogenic cooling on the machinability and hole accuracy of CFRP composites
(Elsevier, 2022) Agrawal, Chetan; Khanna, Navneet; Pimenov, Danil Yu; Wojciechowski, Szymon; Giasin, Khaled; Sarikaya, Murat; Yildirim, Cagri Vakkas
In this work, the drilling performance of carbon fibre reinforced plastic (CFRP) composites is analysed in terms of thrust force (F-n), torque (M-z), specific cutting energy (SCE), delamination factor (F-d), and hole quality under dry and cryogenic cooling conditions. An in-house developed multi-jet liquid nitrogen (LN2) delivery setup is used for experimental trials. This LN2 delivery system is retrofitted to an existing machine tool to enable the movement of jets along the axis of the spindle for better reachability of LN2 to the cutting zone during the drilling operation. Experiments are conducted using the full factorial technique considering four levels of spindle rotational speed (N), four levels of feed rate (f(r)), and two cutting conditions i.e., dry and cryogenic cooling. Results show increased F-n up to 35% and decreased M-z up to 24.46% using cryogenic drilling as compared to dry drilling. Moreover, SCE is reduced up to 35% using cryogenic drilling than in dry drilling. Entry F-d is decreased up to 21.55% under cryogenic drilling as compared to dry drilling. At higher N input and lower f(r), the exit F-d can be reduced by up to 9% using cryogenic drilling as compared with dry drilling. In terms of hole quality, cylindricity (CYL) decreased by up to 42.69%, lower deviation in average hole size, and decreased average surface roughness (R-a) up to 20% when using cryogenic drilling. The results show that using the multi-jet cryogenic cooling system provides enhanced composite machinability and sustainability for industrial use. (c) 2022 The Author(s). Published by Elsevier B.V.
Experimental research on sustainable drilling of Hastelloy X superalloy: Impact of hBN, GNP, LN2 and hybrid eco-friendly cooling/ lubrication strategies
(Elsevier Sci Ltd, 2024) Sirin, Emine; Yildirim, Cagri Vakkas; Kivak, Turgay; Sirin, Senol; Sarikaya, Murat
In this study, the effect of sustainable cooling and lubrication strategies such as MQL, LN2, LN2 +MQL, LN2 +hBN/GA, LN2 +GNP/GA, LN2 +hBN-GNP/GA on drilling nickel-based Hastelloy X alloy was examined. The environmental impacts and health risks of traditional petroleum-based cutting fluids used in drilling operations have led researchers to look for ecological alternatives. In this context, combinations of nanofluids enriched with minimum quantity lubrication (MQL), liquid nitrogen (LN2), and nanosized hBN and GNP particles have been tested. The experiments were carried out at cutting speeds of 20 and 30 m/min and feed rates of 0.04 and 0.06 mm/rev. Nanofluids characteristics i.e., viscosity, Ph, thermal conductivity and wettability, and drilling performance were evaluated with criteria such as cutting force, surface roughness, hole quality and tool wear. The results obtained showed that the hybrid methods combining LN2 and nanofluid-based MQL provided superior performance in terms of both cooling and lubrication, and the condition directly positively affected the processing outputs. This study contributes to the literature by revealing the potential of ecological cooling/lubrication methods in the sustainable production of difficult-to-machine materials such as Hastelloy X.
Influence of MoS2 based nanofluid-MQL on tribological and machining characteristics in turning of AA 2024 T3 aluminum alloy
(Elsevier, 2021) Yucel, Aysegul; Yildirim, Cagri Vakkas; Sarikaya, Murat; Sirin, Senol; Kivak, Turgay; Gupta, Munish Kumar; Tomaz, Italo, V
Aluminum (Al) alloys are of particular importance to the aerospace industry owing to the combination of characteristics including strength, ductility, toughness, fatigue life and oxidation resistance as a light metal. This is the case of AA 2024 T3 Al alloy. In particular, machining of these alloys has similar importance for productivity and part quality. Recently, the use of nanofluids, which have various advantages in terms of both cooling ability and tribological aspects, has become popular for the efficient machining of such alloys. In this context, guiding data are needed that enable industry and researchers to machine these types of alloys with high efficiency. Taking these into account, in this study, AA 2024 T3 Al alloy was machined and various machinability indicators such as surface roughness, surface topography, maximum temperature and dominant tool wear mechanism under different cooling/lubrication strategies i.e., dry cutting, base fluid minimum quantity lubrication (MQL) and mineral oil based MoS2 nanofluid MQL (NFMQL) were investigated. As a results, significant improvements have been achieved in surface roughness, surface topography, and maximum temperature with help of NFMQL application. The intensive built-up edge (BUE) and built-up layer (BUL) formations are produced on the cutting tool when machining AA 2024 T3 Al alloy under dry cutting. On the other hand, BUE formation has been significantly eliminated thanks to NFMQL. Moreover, a less damaged cutting edge was obtained when machining Al alloy under NFMQL compared to both dry cutting and MQL environments. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Investigation of the characteristic properties of graphene-based nanofluid and its effect on the turning performance of Hastelloy C276 alloy
(Elsevier Science Sa, 2022) Babu, M. Naresh; Anandan, V.; Yildirim, Cagri Vakkas; Babu, M. Dinesh; Sarikaya, Murat
The present paper addresses an ecological machining method in turning Hastelloy C 276 Nickel alloy under different conditions such as dry, oil with least quantity lubrication (LQL), and graphene-based nanofluid LQL (NFLQL) by changing the cutting speed (31, 46, and 62 m/min) and feed rate (0.1, 0.15 and 0.2 mm/rev). Four machining responses were studied namely: surface roughness, tool wear, cutting temperature, and chip thick-ness. The wettability, pH value, and stability of the nanofluids were assessed prior to the machining process. The output revealed that the usage of NFLQL enhanced the machining performance in contrast to the oil LQL and dry conditions. The average reduction in the surface roughness with NFLQL condition is about 66% compared to dry machining. In addition, NFLQL gives the lowest cutting temperature (40 C), flank wear (0.053 mm), and chip thickness (0.16 mm) respectively. In a nutshell, the effective cooling and lubrication ability of NFLQL has made significant contributions to smoother machining.
Investigation of the influence of MWCNTs mixed nanofluid on the machinability characteristics of PH 13-8 Mo stainless steel
(Elsevier Sci Ltd, 2020) Ondin, Oguzhan; Kivak, Turgay; Sarikaya, Murat; Yildirim, Cagri Vakkas
In recent years, advances in nanotechnology have been positively reflected in the manufacturing industry, as in many other fields. Owing to their physical and chemical aspects, the nano-sized solid lubricants can help to improve the tribological and thermal properties when added to aerosols, suspensions and emulsions. In order to achieve high efficiency in machining operations, this phenomenon provides an opportunity to perform the tasks expected from a coolant/lubricant. Therefore, this study aimed to investigate the influence of cutting fluid reinforced by multi-walled carbon nanotubes (MWCNTs) into vegetable based cutting fluid on machinability characteristics of PH 13-8 Mo stainless steel that has excellent mechanical properties. For this, Taguchi's L27 (3(3)) orthogonal array involving three factors and their three levels such as cutting speed of 120, 180, 240 m/min, feed rate of 0.1, 0.15 and 0.2 mm/rev and three C/L environment i.e., dry, pure-MQL (0 vol% of nano-additives) and MWCNTs mixed nanofluid-MQL were taken as process parameters. In this experimental design, surface roughness and peak temperature in cutting zone were considered as responses. Moreover, to analyze only the influence C/L environment on tool wear, wear mechanisms and surface topography, a series of experiments were conducted by preserving other machining parameters. As a result, approximately 5% and 12% lower surface roughness was achieved with pure-MQL and nanofluid-MQL, respectively. The reduction in flank wear was found to be 40.2% and 69% under cutting environment, i.e., pure-MQL and MWCNTs mixed nanofluid-MQL.
Machinability performance of nickel alloy X-750 with SiAlON ceramic cutting tool under dry, MQL and hBN mixed nanofluid-MQL
(Elsevier Sci Ltd, 2021) Sirin, Senol; Sarikaya, Murat; Yildirim, Cagri Vakkas; Kivak, Turgay
Nickel alloy X-750 which is difficult-to-machine material, is employed in many critical fields owing to its superior mechanical and thermal properties. However, these superior features lead to some difficulties in its machinability especially when using carbide tool materials. Hence, ceramic cutting tools (CCTs) having excellent hardness, heat and abrasion resistance, and poor chemical proximity to workpiece material are a perfect choice in machining operations of such materials. Considering this, the current study focused on the influence of various cutting environment, i.e., dry, base fluid-MQL without any mixed nanoparticles (BF-MQL) and hBN dispersed nanofluid-MQL (NF-MQL) on surface roughness, 2D-surface topography, maximum cutting temperature, cutting force, micro-hardness, flank wear and its mechanism when milling of alloy X-750 with Sialon ceramic tools. As a result, surface roughness was reduced by about 39% and 47.2% with BF-MQL (0 vol% additive) and hBN mixed NF-MQL, respectively compared to dry machining environment. Also the noticeable improvement with NF-MQL environment in 2D-surface topography of workpice, cutting temperature and cutting force has been achieved, the dry machining offered less tool wear for CCT than both BF-MQL and NF-MQL.
Optimization of MQL Parameters Using the Taguchi Method in Milling of Nickel Based Waspaloy
(Gazi Univ, 2017) Yildirim, Cagri Vakkas; Kivak, Turgay; Erzincanli, Fehmi; Uygur, Ilyas; Sarikaya, Murat
This study aimed to investigate the effect of the minimum quantity lubrication (MQL) parameters such as cutting oil type, flow rate, milling method, pulverization distance and nozzle type on average surface roughness (Ra) in milling of nickel based Waspaloy super alloy. During milling experiments, constant cutting speed (45 m/min), feed rate (0.1 mm/rev) and depth of cut (0.5 mm) were selected as machining parameters. Four different types of oil (vegetable, synthetic, mineral and mineral-synthetic), four different flow rates (25, 50, 75 and 100 ml/h), two different milling methods (down milling and up milling) two pulverization distances (25 and 50 mm) and two different nozzle types were chosen as MQL parameters. The results were analyzed using 3D surface graphs, signal-to-noise ratio (S/N) and main effect graphs of means. Optimal MQL parameters were determined using the S/N ratio. Mathematical models have been created for surface roughness. The analysis results indicated that the dominant factors were oil type and flow ratio on surface roughness. In addition, confirmation test results showed that the Taguchi method was very successful in the optimization of MQL parameters in order to obtain minimum surface roughness in milling of Waspaloy super alloy.
Performance evaluation of MQL with AL2O3 mixed nanofluids prepared at different concentrations in milling of Hastelloy C276 alloy
(Elsevier, 2020) Gunan, Fatih; Kivak, Turgay; Yildirim, Cagri Vakkas; Sarikaya, Murat
Since some deficiencies in mist lubri-cooling techniques i.e., minimum quantity lubrication (MQL) in heavy cutting conditions have been noticed, recently nano-cutting fluids which have enrich thermal conductivity than base fluid, are begun to be used in MQL system. One of the critical issues arising in this process is the addition of the appropriate nanoparticle ratio to the base liquid. Therefore, this study aimed to find the optimum distribution rate of Al2O3 nanoparticles having excellent properties and machining parameters. For this purpose, by adding Al2O3 nanoparticles to vegetable-based cutting fluid, nano-cutting fluids were prepared in different volumetric concentrations (0.5, 1.0 and 1.5 vol%). These prepared nanofluids were used in the MQL system when milling of Hastelloy C276. Three cutting speeds (60, 75 and 90 mirnin) and three different feed rates (0.10, 0.15 and 0.20 mm/rev) were added to the experimental design to study the performance of nanofluids under several cutting parameters. Apart from this experimental design, to clearly see the effect of concentration rates on tool wear and tool life, three experiments were carried out at each concentration ratio by keeping the machining parameters. Eventually, 1 vol% Al2O3 concentration clearly provided an improvement by up to 23% and 10% in tool life, compared to 0.5 vol% and 1.5 vol% concentration, respectively. In addition, while chipping/fracture, attrition wear and peeling of coating were observed under all cutting conditions, there was no evidence for workpiece material adhesion at 1 vol% and 1.5 vol% Al2O3 based nanofluid-MQL. (C) 2020 The Authors. Published by Elsevier B.V.
Performance evaluation of whisker-reinforced ceramic tools under nano-sized solid lubricants assisted MQL turning of Co-based Haynes 25 superalloy
(Elsevier Sci Ltd, 2021) Sarikaya, Murat; Sirin, Senol; Yildirim, Cagri Vakkas; Kivak, Turgay; Gupta, Munish Kumar
Ceramics are widely used in machining of high temperature alloys i.e., Co-based Haynes 25 alloy due to its superior characteristics. The present paper is focused on the performance of whisker-reinforced ceramic cutting tool (WRCCT) under nano-sized solid lubricants dispersed in MQL (nanofluid-MQL) during turning of Co-based Haynes 25 alloy. The turning experiments were performed under several cutting environments (dry, base fluid MQL (BF-MQL), hBN based nanofluid MQL (hBN-NMQL), MoS2 based nanofluid MQL (MoS2-NMQL), graphite based nanofluid MQL Gr-NMQL) by varying cutting speed (200 and 300 m/min) and feed rate (0.1 and 0.15 mm/ rev) values. Initially, the viscosity and thermal conductivity of nanofluids were evaluated and then the prepared nanofluids were used for machining experiments. The results reveal that the rate of increase in thermal conductivity coefficient relative to base cutting fluid was 11.90% in hBN-nanofluid, 16.29% in MoS2-nanofluid and 14.12% in Gr-nanofluid. In terms of machining performance, on the one hand, the minimum surface roughness was obtained from Gr-NMQL assisted machining, on the other hand, the hBN-NMQL has been successful in limiting of notch wear and nose wear values. Compared to dry turning, the temperature was reduced up to 27.18% with hBN doped nanofluids, while it was 34.95% with MoS2 doped nanofluids and 29.32% with graphene doped nanofluids.
Performance of cryogenically treated carbide inserts under sustainable cryo-lubrication assisted milling of Inconel X750 alloy
(Elsevier, 2021) Sirin, Senol; Yildirim, Cagri Vakkas; Kivak, Turgay; Sarikaya, Murat
Owing to their superior features even under elevated temperatures, the nickel-based superalloy Inconel X750 is among the materials demanded in many critical areas. However, such alloys are hard to cut because of their characteristic properties i.e., strain hardening, poor thermal conductivity, high mechanical resistance at elevated temperature, the presence of abrasive carbide fragments and chemical proximity. Therefore, it is important to develop the machinability characteristics of these materials with sustainable machining methods that offer high performance. For this, in this work, a number of attempts were made during the milling of the Inconel X750 alloy. During the experiments, the performance of each cutting tool was investigated by considering three different tools which are uncoated carbide tool, cryogenically treated cutting tool and TiAlN coated tool. Since the machinability of superalloys is difficult in the dry environment, three different sustainable cooling/lubrication conditions such cryogenic LN2, MQL and hybrid cooling/lubrication (MQL + LN2) have been used in conjunction with these tools. In evaluating the effectiveness of the employed methods, flank wear, tool damage types, surface roughness/topography, cutting force and maximum temperatures were analyzed. As a result, even if the cryogenically treated tool performed slightly better than those of untreated, it still did not reach the performance level of the TiAlN coated tools. The hybrid cooling/lubrication system with coated tool offered the best solution in terms of all criteria. On the other hand, MQL outperforms LN2 cooling for tool wear, surface roughness/topography and cutting force, LN2 cooling is better than MQL in temperature reducing.
Resource conservation and sustainable development in the metal cutting industry within the framework of the green economy concept: An overview and case study
(Elsevier, 2022) Kshitij, G.; Khanna, Navneet; Yildirim, Cagri Vakkas; Dag, Salih; Sarikaya, Murat
The metal cutting industry has an important role in the growth of the global economy. In this industry, while research is made on factors such as cutting tool, cooling/lubrication environments, improved cutting parameters, etc., for increased productivity, serious efforts are also made to obtain environmentally friendly and healthy processes. Based on recent developments in tool materials, cutting speeds have increased significantly in machining operations. However, the increased temperatures with increasing cutting speeds have also reduced productivity and caused resource and product losses. The use of cutting fluids, especially in the machining of superalloys, has a vital task in reducing the problems. However, petroleum-based cutting fluids, which are still frequently used and have an important share in the industry, do not comply with the concept of a green economy due to environmental effects and costs. For this reason, the use of sustainable cutting fluids and optimum pa-rameters in metal cutting industry processes has become a necessity. From this perspective, this study was carried out in two stages. In the first stage, the outputs of the metal cutting industry were examined within the scope of the principles of green economy. In the second stage, a case study was then conducted involving the machining of Inconel 718 and Ti6Al4V alloys at different cutting speeds and under LCO2. In the case study, critical outputs, both from an economic and sustainability point of view, namely cutting tool wear, surface roughness, specific energy consumption, machining costs and carbon emissions are examined. The results obtained in the machining of both materials were compared with each other. Total cost and carbon emissions can be reduced by up to 35% and 7%, respectively, under the appropriate parameter combination and LCO2 cooling conditions.
Study on turning performance of PVD TiN coated Al2O3+TiCN ceramic tool under cutting fluid reinforced by nano-sized solid particles
(Elsevier Sci Ltd, 2020) Kivak, Turgay; Sarikaya, Murat; Yildirim, Cagri Vakkas; Sirin, Senol
Due to their excellent chemical stability, hardness and abrasion resistance, ceramic cutting tools are suitable for operations at very high cutting speeds, which play a decisive role in high productivity. Thanks to these properties, they are significantly resistant to high temperatures occurred in the cutting zone. However, after a certain point, excessive temperature rise in the cutting zone brings some problems. This is seen as a problem that should be overcome as it affects negatively machining efficiency. However, the poor resistance of ceramic tools to thermal shocks is an important factor restricting the use of flood cooling. Alternatively, promising results have been achieved recently in MQL and nanofluid-MQL applications particularly on carbide cutting tools. When these methods are used together with ceramic cutting tools, the behavior of ceramic cutters and their effect on machinability outputs is still a matter of curiosity. Therefore, in order to observe the interaction between ceramic cutting tool and minimum quantity lubrication (MQL) and nanofluid-MQL, we investigated the turning performance of PVD TiN coated Al2O3+TiCN ceramic tool under dry, pure-MQL and nanofluid-MQL reinforced by nano-sized solid particles such as graphene nanoplatelets (GNPs) and multi walled carbon nanotubes (MWCNTs). Experiments were carried out to investigate the effect of cooling/lubrication (C/L) environment and cutting parameters on tool life, surface roughness and maximum temperature of chip. In addition, a series of experiments were also made to observe the effect of only C/L environment on the wear behavior of the ceramic tools and the machined surface topography while keeping the cutting parameters constant. As a result, pure-MQL contributed to the reduction of nose wear by about 69% compared to dry machining, while GNPs based nanofluid-MQL helped to reduce the surface roughness by 19.42%.
The effect of addition of hBN nanoparticles to nanofluid-MQL on tool wear patterns, tool life, roughness and temperature in turning of Ni-based Inconel 625
(Elsevier Sci Ltd, 2019) Yildirim, Cagri Vakkas; Sarikaya, Murat; Kivak, Turgay; Sirin, Senol
Nickel-based Inconel 625 is employed in critical applications because of its excellent properties. But the machinability of this material is very poor. In recent years, the use of minimum quantity lubrication has gained prominence to improve machining performance without increasing the oil. However, pure-MQL may be insufficient for machining of difficult-to-machine materials. This paper focused on the development of nano-MQL by adding ISBN nanoparticles compared to pure-MQL and dry machining in turning of Inconel 625. Tool life, surface roughness, tool wear and tool-chip interface temperature were analyzed. Wear mechanisms were evaluated by SEM photographs and EDX analysis. The results showed that; 0.5 vol% hBN nanofluid has produced promising results for low tool wear and roughness and high tool life.
The effect of nanofluids reinforced with different surfactants on the machining and friction-wear properties of Waspaloy
(Elsevier Sci Ltd, 2023) Yildirim, Cagri Vakkas; Sirin, Senol; Kivak, Turgay; Sarikaya, Murat
In present investigation, a number of experiments were done to determine the impact of surfactants on Waspaloy machining characteristics and the friction-wear behavior on the ball-on-disc tester. The experiments were carried out in dry, base fluid (sunflower oil), Cuo, and ZnO nanofluid conditions with/without surfactant. Four distinct surfactants, including Gum Arabic (GA), Sodium Dodecyl Sulfate (SDS), CeTyltrimethylAmmonium Bromide (CTAB), and PolyVinyl Pyrrolidone (PVP), were employed to prepare the nanofluids with surfactant. In addition, viscosity, pH, and thermal conductivity measurements were made to determine the prepared nanofluid's thermo-physical properties. Tool wear and its mechanisms, surface roughness and cutting temperature in machining experiments, coefficient of friction (CoF), microhardness, and wear track width in ball-on-disk tests were choosen as evaluation criterias. From both the machining and ball-on-disk test results, it was determined that the ZnO + PVP nanofluid condition outperformed the other conditions. The ZnO + PVP nanofluid condition provided 53.9 %, 36.52 %, and 44 % improvement in tool wear, surface roughness, and cutting temperature, respectively, compared to the dry cutting condition. Also, considering the results of the ball-on-disk test, it was found that the CoF and width track width values for the ZnO+PVP nanofluid condition were both 76.02 % and 56.11 % lower than the dry condition.

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