Yazar "Sirin, Senol" seçeneğine göre listele
Listeleniyor 1 - 13 / 13
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Analysis of machinability and sustainability aspects while machining Hastelloy C4 under sustainable cutting conditions(Elsevier, 2023) Yildirim, cagri Vakkas; Sirin, Senol; Dagli, Salih; Salvi, Harsh; Khanna, NavneetIn recent years, developments in the defense, aerospace, and medical industries have significantly increased the expectations regarding material performances. In particular, the demand for materials that can withstand very high and/or very low temperatures and harsh mechanical/chemical conditions has increased. The superior qualities of superalloys can adequately meet this demand. However, the difficulties encountered in the machining of these alloys cause some burdens both ecologically and economically due to the use of cutting fluid. Therefore, the use of cost-friendly and sustainable cutting fluids in the production industry has a vital role, both in terms of machining performance and the environment. From this perspective, this paper focuses on the effects of various cutting environments, i.e., Dry, MQL, LN2, N-2, CO2, Vortex, LN2 + MQL, N-2 + MQL, CO2 + MQL, and Vortex +MQL on the machining performance of Ni-based C4 alloy. Additionally, it was aimed to reveal the effect of cooling/lubrication methods on sustainability by performing a sustainability analysis. Firstly, surface roughness, power consumption, tool wear and mechanisms, and cutting temperature were considered as performance characteristics. When examined in terms of machinability, Vortex + MQL gave the best result in terms of surface roughness and power consumption, while LN2 gave the best result in terms of cutting temperature. Then, a comprehensive sustainability analysis was carried out. As a result, the CESMO follows the order of Dry > MQL > LN2 > LN(2 +)MQL > CO2 > CO2 + MQL > N-2 > N-2 + MQL > Vortex > Vortex + MQL. While employing Vortex + MQL cutting condition, the CESMO decreased by about 11.37% as compared to Dry cutting condition. While using a combination of different sustainable lubrications or coolants, the overall carbon emissions decreased in the range of about 15-25% approximately as compared to the employment of the individual cutting conditions (i.e., coolant/lubricants).Öğe 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, MuratThe 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.Öğe Comparison of VT-20 alloy drilling performance evaluation under dry, MQL, EMQL, and hybrid nanoparticle assisted EMQL ecological conditions(Elsevier Sci Ltd, 2024) Khanna, Navneet; Shah, Prassan; Singla, Anil Kumar; Bansal, Anuj; Makhesana, Mayur A.; Sirin, SenolThe potential of VT-20, a titanium (Ti) alloy in the aircraft industry, is increased as it has stronger thermal capabilities than other pseudo-alpha-Ti alloys. However, the alloy's low heat conductivity and chemical reactivity make machining difficult and necessitate efficient cooling/lubrication. Cutting oils based on emulsion have been used to move heat from the cutting region; however, they are not sustainable due to their negative impacts on workers' health and the environment. Therefore, this novel study investigates alternative lubricating approaches, such as drilling VT-20 alloy under dry, MQL, EMQL, and HNPEMQL conditions using SEM and line-scan EDS analysis. An indigenously developed electrostatic minimum quantity lubrication (EMQL) and hybrid nanoparticles (NPs) immersed in EMQL (HNPEMQL) techniques were utilized to improve drilling performance while reducing cutting oil consumption. Hybrid nanofluids for HNPEMQL application were developed using aluminium oxide (Al2O3) and plate-structured graphene nanoparticles using a two-step process. The surface quality of the drilled hole, tool wear, thrust force, power consumption, hole quality indicators, and microhardness are evaluated. The efficacy of HNPEMQL showed improved drilling efficiency compared to dry, MQL, and EMQL machining. HNPEMQL, EMQL, and MQL conditions reduced tool wear by 102 %, 53 %, and 19%, respectively, to dry drilling. The HNPEMQL condition lowered the thrust force by 75.3 %, 28.69 %, and 18.02 %, respectively, compared to the dry, MQL, and EMQL. HNPEMQL demonstrated a 105 %, 41 %, and 22 % reduced variation in circularity values than dry, MQL, and EMQL for the same number of drilled holes. The findings show that HNPEMQL can be considered a promising cooling and lubricating strategy with improved drilling performance and quality.Öğe Effect of hBN and SDS added vegetable based cutting fluid application on the performance of turning Ti6Al4V alloys: A Comparative analysis with Taguchi and ANN approaches(Elsevier Science Sa, 2024) Celik, Muhammet; Sencan, Aysegul Cakir; Sirin, Senol; Erdogan, Beytullah; Sencan, CevdetIn this study, during the turning process of Ti6Al4V alloy, which is difficult to machine, nanofluid, whose base fluid is vegetable oil (sunflower oil), was applied to the cutting zone with the minimum quantity lubrication (MQL) technique. Nanofluids were prepared by adding hexagonal boron nitride (hBN) nanoparticles (65-75 nm) with different concentration ratios (0.5 and 1 %) and surfactant (Sodium dodecyl sulfate, SDS) into vegetable oil. Thermal conductivity coefficients and dynamic viscosities of the prepared nanofluids and pure sunflower oil were measured at four different temperatures. Additionally, the stability of the prepared nanofluids was observed for 15 months. In turning experiments, four different cutting speeds (50, 75, 100 and 125 m/min), four different feed rates (0.05, 0.10, 0.15 and 0.20 mm/rev) and four different cooling conditions (dry, PureMQL, 0.5 % NanoMQL and 1 % NanoMQL) were used. The effect of the change in these parameters on surface roughness (Ra),temperature in the cutting zone (T) and flank wear on the tools (Vb) was investigated experimentally and analytically. As a result of the research, the experimental results were evaluated using variance analysis, signal/ noise (S/N) analysis and artificial neural networks (ANN) methods. As a result of the measurements and observations, it was determined that the nanofluid with 0.5 % concentration had the best stability. In the main experiments, the MQL condition using this nanofluid (0.5 % NanoMQL) exhibited the best machining performance. In the wear experiments, the lowest tool wear was detected under the 1 % NanoMQL condition. According to the ANOVA and S/N analysis results showed that Ra was most affected by the feed rate (95 %), T was most affected by the cooling condition (70 %), and Vb was most affected by the cutting speed (45 %). The prediction performances of ANN and Taguchi approaches were examined and the prediction success of these approaches was more than 98.5 % and 80.8 %, respectively. Especially for Vb values that have very close data, more accurate predictions were made with the ANN approach compared to Taguchi.Öğe Effects of hybrid nanofluids on machining performance in MQL-milling of Inconel X-750 superalloy(Elsevier Sci Ltd, 2021) Sirin, Senol; Kivak, TurgayFriction and high temperatures greatly affect machining efficiency when machining superalloy materials. Nanoparticles with high thermal conductivity and lubricity are preferred for increase lubricant performance. Nanofluids prepared with nanoparticles not only reduce environmental concerns but also positively affect the machining efficiency in the sustainable manufacturing process. However, some nanoparticles added in mono form stand out with their thermal conductivity and some nanoparticles with their lubricating performance. For this reason, the lubrication performance of hybrid nanofluids prepared with nanoparticles with different superior properties is a matter of interest. In this study, the machining performance of Inconel X-750 superalloy was investigated by using hexagonal boron nitride (hBN), graphite (Grpt), and MoS2 nanoparticles with different shapes and properties. For this purpose, the milling experiments were performed under three different hybrid nanofluid (hBN/Grpt, hBN/MoS2, and Grpt/MoS2) conditions, at three different cutting speeds (30, 45, and 60 m/min), and three different feed rates (0.05, 0.10, and 0.15 mm/rev). Cutting force, cutting temperature, surface roughness/topography, tool wear, and tool life were selected as machining performance criteria. According to the results obtained from the experiments, it was understood that the hBN/Grpt hybrid nanofluid outperformed hBN/MoS2 and Grpt/MoS2 conditions in all performance criteria. hBN/Grpt hybrid nanofluid achieved 36.17% and 6.08% improvement in tool life compared to Grpt/MoS2 and hBN/MoS2 nanofluids, respectively.Öğe Evaluation of machining characteristics of SiO2 doped vegetable based nanofluids with Taguchi approach in turning of AISI 304 steel(Elsevier Sci Ltd, 2024) Sencan, Aysegul Cakir; Sirin, Senol; Sarac, Ekin Nisa Selayet; Erdogan, Beytullah; Kocak, Mueberra RuveydaIn this study, nanofluids prepared by incorporating silicon dioxide (SiO2) nanoparticles into sunflower oil were used as cutting fluids for turning AISI 304 stainless steel. Dynamic viscosities and thermal conductivities of nanofluids prepared at two different concentrations (1 % and 0.5 % by volume) were measured at four different temperature conditions. The experiments were carried out in two stages: main experiments and additional experiments. In the main experiments, four different cooling conditions (dry, PureMQL, 0.5 % NanoMQL, 1 % NanoMQL), four different cutting speeds (80, 120, 160, 200 m/min), and four different feed rates (0.10; 0.15, 0.20, 0.25 mm/rev) were used. In additional experiments, the effect of 4 different cooling methods on machining performance was investigated by keeping the maximum cutting speed (200 m/min) and feed rate (0.25 mm/rev) constant. In all experiments, workpiece surface roughness (Ra), temperature in the cutting zone (T), and flank wear on cutting tools (Vb) were determined as performance criteria. Also, additional experiments were repeated 45 times, and wear was measured every ten experiments to get a clearer picture of the tool wear process. At the end of the study, it was determined that the most effective parameter on surface roughness was feed rate (76 %), while the temperature in the cutting zone and tool wear were mainly affected by the cooling method (80 % and 50.5 %, respectively). The best machining performance was observed in the 0.5 % nanoMQL method.Öğe Evaluation of the tribological performance of the green hBN nanofluid on the friction characteristics of AISI 316L stainless steel(Emerald Group Publishing Ltd, 2021) Akincioglu, Sitki; Sirin, SenolPurpose The purpose of this study is to investigate the effect of new green hexagonal boron nitride (hBN) nanofluid on AISI 316L stainless friction coefficient, wear resistance and wear using a ball on disc tester. Design/methodology/approach Nanofluids were prepared by adding hBN nanoparticles with two-step method to the vegetable-based oil at 0.50 vol%. Before the experiments, hBN nanofluid viscosity, pH and thermal conductivity specifications were determined. Friction tests of AISI 316L stainless steel were performed under 2 N, 5 N and 8 N loads at 400 rpm using a ball-on-disc test device under dry, oil and hBN conditions. Coefficient of friction, wear profile, surface integrity and wear mechanisms were chosen as performance criteria. Findings The friction coefficient values obtained under the oil and hBN test conditions with the 8 N load were, respectively, 72.46% and 77.64% lower than those obtained under dry test conditions. hBN nanofluid performed better on surface topography, and especially wear, compared to the dry and oil test conditions. Practical implications The aim of this study was to determine the best tribological performance of the hBN nanofluid on AISI 316L stainless steel used in orthopedic applications. Originality/value The paper is a study investigating the effect of hBN nanoparticle additive in vegetable-based oil on friction and wear performance of AISI 316L stainless steel. It is an original paper and is not published elsewhere.Öğe Machinability performance of different fiber orientations of roll wrapped CFRP pipes(Wiley, 2024) Yilmaz, Merve; Kilincel, Mert; Sirin, SenolIntegrating fiber reinforcement plastics (FRP) materials into the industry plays a key role especially for pipes. However, due to the production methods of CFRP pipes, surface finishing processes are inevitable at the end of production. Despite the widespread use of CFRP materials, the predominant focus in the literature has been on their mechanical performance. This study aims to contribute to the limited research on the machinability of CFRP materials. In this context, the turning machining process for CFRP pipes was experimentally investigated in the present study. For this purpose, carbon fiber pipes with an inner diameter of 30 mm and an outer diameter of 60 mm were produced and subjected to computer numerical control (CNC) turning. First, a cylindrical aluminum pipe is used as a mold to manufacture CFRP pipes. Unidirectional (UD) carbon fabrics were wrapped on these aluminum molds. Shrink tape was used to enhance the surface smoothness and required pressure to prevent delaminating of the end product during the process. UD carbon fabrics are wrapped on to the mold at the selected angles (0 degrees, 45 degrees, and 90 degrees) and the CFRP pipe specimens were manufactured using epoxy matrix. Pipes were processed on CNC lathe at 120, 160, 200 rev/min speeds and f 0.4 mm/rev feed rate. The surfaces of the machined specimens were measured with a microscope and a surface roughness device. On the other hand, wear on the tools was observed after the process.Öğe 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, TurgayNickel 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.Öğe 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 KumarCeramics 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.Öğe 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, MuratOwing 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.Öğe Real-time monitoring and measurement of energy characteristics in sustainable machining of titanium alloys(Elsevier Sci Ltd, 2024) Gupta, Munish Kumar; Korkmaz, Mehmet Erdi; Yilmaz, Hakan; Sirin, Senol; Ross, Nimel Sworna; Jamil, Muhammad; Krolczyk, Grzegorz M.The development of cutting-edge monitoring technologies such as embedded devices and sensors has become necessary to ensure an industrial intelligence in modern manufacturing by recording machine, process, tool, and energy consumption conditions. Similarly, machine learning based real time systems are popular in the context of Industry 4.0 and are generally used for predicting energy needs and improving energy utilization efficiency and performance. In addition, sustainable and energy-efficient machining technologies that can reduce energy consumption and associated negative environmental effects have been the latest topic of much study in recent years. Concerning this regard, the present work firstly deals with the real time monitoring and measurement of energy characteristics while machining titanium alloys under dry, minimum quantity lubrication (MQL), liquid nitrogen (LN2) and hybrid (MQL + LN2) conditions. The energy characteristics at different stages of machine tools were monitored with the help of a high end energy analyser. Then, the energy signals from each stage of machining operation were predicted and classified with the help of different machine learning (ML) models. The experimental results showed that MQL, LN2, and hybrid conditions decreased the total energy consumption by averagely 2.6 %, 17.0 %, and 16.3 %, respectively, compared to dry condition. The ML results demonstrated that the accuracy of the random forest (RF) approach obtained higher efficacy with 96.3 % in all four conditions. In addition, it has been noticed that the hybrid cooling conditions are helpful in reducing the energy consumption values at different stages.Öğe 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, SenolDue 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%.
