Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2026Scopus SJRQ2Investigation of the effect of ultrasonic assisted milling and minimum quantity lubrication methods on the machinability of Hardox 500 steel
Dalgıç, Aras; Mahmat, Aybars
Hardox steel is widely used in agriculture, mining and transportation due to its mechanical properties such as high wear resistance, high impact resistance, high hardness, high durability and long life. The machinability of Hardox 500 is difficult as its high hardness and wear resistance lead to tool wear and low machining speed. Recently, various processing and cooling methods have been developed to increase machinability. Ultrasonic assisted milling (UAM), one of these methods, is a method used as an alternative to conventional milling (CM) in the milling of traditionally difficult-to-machine materials. In addition, minimum quantity lubrication (MQL) is a cooling method used to provide lubrication and cooling in the cutting area. In this study, the impacts of machining method, feed rate and spindle speed on cutting force, surface roughness and tool wear in milling of Hardox 500 steel were investigated. In the MQL method, mixtures with nano-sized SiC particles were obtained and applied to the cutting area. In the study, MQL reduced cutting forces by up to 19 %, surface roughness by 18 %, and tool wear by 30 % compared to dry machining, while UAM further decreased cutting forces by 17 %, surface roughness by 15 %, and tool wear by 12 % compared to CM. These results demonstrate that MQL and UAM significantly enhance machining performance over conventional and dry methods.
- MakaleAçık Erişim2025Scopus SJRQ2Ultrasonic-assisted high-speed micro-milling of Ti6Al4V
Mahmat, Aybars; Agar, Salih; Tosun, Nihat
In this study, the effects of different cooling techniques and process parameters on the performance characteristics of ultrasonic and conventional micro-milling (1-micron fixed amplitude, 20 and 30 kHz frequencies) of Ti6Al4V alloy were experimentally investigated. The impact of independent factors on tool life, cutting force, surface topography, surface roughness and cutting temperature was determined in order to find out machinability characteristics in this paper. Machining operations were performed under 20,000, 40,000 and 60,000 rpm revolution speed. The cutting depth and feed rate of the machining were kept fixed at 0.02 mm and 0.66 mm/s, respectively. Uncoated carbide and TiSiN-coated carbide cutting tools were used in machining operations. Dry machining and two different minimum quantity of lubrication (MQL) methods were used as cooling methods. According to the results achieved in the existing study, the ultrasonic micro-milling improved the surface roughness, reduced cutting forces, cutting zone temperature, and cutting tool wear. It was also found that MQL methods among other methods used in the present study have a greater effect on performance characteristics. As the spindle speed increased, the workpiece surface roughness, cutting force and tool life decreased, while the cutting zone temperature increased.
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İncele - MakaleYalnız künye2025Scopus SJRQ2Investigation of Mechanical Properties of Jute and Tea Waste-Reinforced Epoxy Composite Material Produced by Vacuum Assisted Resin Infusion Molding
Dogan, Akar; Mahmat, Aybars; Agar, Salih
Recently, the production of materials obtained from plant sources has been increasing due to their environmentally friendly and sustainable sources. Natural fibers and waste materials offer a remarkable alternative in composite production due to their biodegradability, low cost and renewability. In this study, composite materials were produced using hybrid Jute and industrial tea waste-reinforced epoxy materials by vacuum assisted resin infusion molding. In this context, the reason for using natural and industrial resources such as jute fiber and tea waste is to contribute to both the improvement of mechanical properties and the reduction of environmental impacts. It was observed that tensile and flexural strength decreased as the amount of tea waste increased. Conversely, the energy absorbed during the quasi-static punch shear and Charpy impact tests increased, unlike the tensile and flexural strength. Approximately 50% decrease was observed in the tensile strength of the 60% tea waste reinforced material compared to the pure jute composite material. In Charpy impact and quasi-static punch shear tests, a 5% increase in the energy absorbed in the 60% tea waste reinforced composite materials was obtained.
AtıfScopus2WoS1OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ2Modeling and analysis of WEDM with a new deep neural network
Mahmat, Aybars; Dogan, Gurkan; Ergen, Burhan; Tosun, Nihat
In some cases, the models targeted in machining processes are difficult to apply to industrial production. Artificial intelligence techniques applied to industrial production methods in recent times eliminate these problems in machining. The use of deep learning methods in solving these problems has recently increased. In this study, a new deep neural network (DNN) based on artificial neural networks is proposed to model the machining of AISI4140 steel by wire electrical discharge machining (WEDM). The proposed DNN model predicts surface roughness (SR) and wire wear ratio (WWR), which are the most important inferences in cutting with WEDM. Obtaining inferences such as SR and WWR in a real experimental environment means a lot of time and cost. With the proposed model, there is a significant reduction in time and cost factors. The dataset used to train and test the proposed model was obtained from the real experimental environment. For training and testing the model, the data set is divided into two parts: 20% test data and 80% training data. In the experimental tests carried out with the proposed model, error rates such as Mean Absolute Error (MAE), R2, and Mean Squared Error (MSE) accuracy rate between SR and WWR values estimated according to the SR and WWR values obtained from the real environment were examined. MAE, MSE, and R2 for SR reached 0.0495, 0.0005, and 98.48%, respectively, while MAE, MSE, and R2 for WWR reached 0.0156, 0.0036, and 98.39%, respectively. These results of the proposed model provided a lower error rate and higher accuracy than the state-of-the-art models in the literature.
AtıfScopus5WoS5OpenAlex7İncele - MakaleYalnız künye2025Scopus SJRQ2Experimental comparison of conventional and ultrasonic-assisted high-speed drilling of glass fiber reinforced epoxy composites
Ağar, Salih; Mahmat, Aybars; Doğan, Akar
Glass fiber reinforced epoxy composites are favored in several industries, including automotive and aerospace, owing to their superior strength-to-weight ratio. Drilling is a prevalent machining procedure employed to add fasteners for laminate assembly. Nonetheless, drilling these composites presents significant challenges due to the abrasive characteristics of the reinforcement, necessitating an examination of machining performance. During the drilling of composites, cutting temperature, thrust force, and delamination damage are primary concerns. In recent years, high-speed ultrasonic drilling, an innovative machining technique designed to address these challenges, has garnered significant interest. This investigation involved high-speed ultrasonic drilling and conventional drilling of glass fiber reinforced epoxy material. In the studies, optimal conditions were studied by evaluating thrust force, cutting temperature, and delamination damage by varying speeds, feed rates, and frequencies. The thrust force was 11 N in the traditional approach at 40,000 rpm, but it was recorded at 9 N with the ultrasonic method. Moreover, with ultrasonic drilling, cutting temperatures decreased by over 25% relative to traditional drilling, attributable to the harmonic motion that dissipates heat in the drilling zone. Analysis of the drilling region revealed a notable enhancement in damage, particularly in delamination, with the application of ultrasonic drilling. The experimental results indicate that ultrasonic machining enhances machining performance.
- MakaleAçık Erişim2024Investigation of tool wear and thrust force in drilling aisi 316 austenitic stainless steel using electrophoresis method
Mahmat, Aybars
Cutting tool costs are an important component of machining. For this reason, improving machining methods in machining affects the life of the cutting tool. Recently, various machining methods have been used to extend tool life by reducing cutting tool wear. One of these methods is electrophoresis-assisted processing. Electrophoresis-assisted machining is a non-traditional machining method created by the impact of abrasive nanoparticles on the machining area with the help of the generated electric field. Electrophoresis-assisted machining increases the machinability of difficult-to-machine materials with high strength and hardness properties compared to traditional machining methods. In this study, the impacts of various cutting parameters on the drilling performance of AISI 316 L stainless steel material were searched using electrophoresis-assisted drilling (EAD) and conventional drilling (CD) methods. In the study, SiC powder was used as nanoparticles in the solution obtained to create the electric field. Within the scope of the experiments, the effects of different machining methods, cutting speeds and feed rates on thrust forces and cutting tool wear values were experimentally examined. As a result of the investigations, the cutting tool wear and thrust cutting force obtained with EAD are better than CM. Increasing feed rate and cutting speed increased cutting tool wear in both machining methods. It has been determined that the thrust force decreases as the cutting speed increases, while it increases as the feed rate increases.Keywords: Electrophoresis, drilling, cutting force, tool wear, AISI 316
- MakaleAçık Erişim2024Hardox 500 Çeliğinin Delinmesinde Minimum Miktarda Yağlama Yönteminin Yüzey Pürüzlülüğü ve Kesme Sıcaklığına Olan Etkisinin İncelenmesi
Mahmat, Aybars
Hardox 500 aşınma ve kırılmalara karşı dirençli, yüksek sertlik ve mekanik muka-vemete sahip sertleştirilmiş bir çeliktir. Bu yüksek mekanik özellikler bu malzemenin işlenebilirliğini sınırlamaktadır. Bu çalışmanın amacı işlenmesi zor olan Hardox 500 çeliğine farklı soğutma yöntemleri ve işleme parametrelerinin uygulanmasıyla işle-nebilirliğini artırmaktır. Endüstriyel açıdan önemli bir malzeme olan Hardox 500 çeliğinin çeşitli kesme ortamları kullanılarak işlenebilirliğini artırmak amaçlanmış-tır. Farklı ilerleme hızları, kesme hızları ve soğutma yöntemlerinin yüzey pürüzlü-lüğüne, kesme sıcaklıklarına, takım aşınmasına olan etkisi incelenmiştir. Deneysel sonuçlara göre Minimum miktarda yağlama (MMY) yöntemi yüzey kalitesini artır-dığı ve yan yüzey aşınması ile kesme sıcaklıklarını düşürdüğü görülmüştür. Kuru koşullara göre MMY yöntemi kullanılarak yüzey pürüzlülüğünde yaklaşık %20-30, kesme sıcaklığında yaklaşık %15-35 yan yüzey aşınmasında %22-30 oranında iyi-leşme elde edilmiştir. Yüzey kalitesini optimize etmek için yüksek kesme hızı ve düşük ilerleme hızlarının seçilmesi gerektiği görülmüştür. Yüksek kesme hızı ve ilerleme hızı sürtünmeyi artırarak sıcaklığı artırmıştır.
- MakaleAçık Erişim2024Scopus SJRQ1Investigation of the effect of electrophoresis-assisted milling on machinability
Mahmat, Aybars
In this study, the electrophoresis-assisted milling (EAM) method, an alternative method to the conventional milling (CM) method, was proposed to increase the machinability of Ti6Al4V alloy, which is difficult to machine. The nanoparticles in the electrophoresis solution generated an electric field. This electric field collected abrasive particles around the cutting tool, and the machining quality was improved. The impacts of different cutting parameters on the performance characteristics were examined using both EAM and CM methods. The experimental results demonstrate that the proposed EAM method significantly improves these performance characteristics. In addition, increasing spindle speed increased tool wear and cutting temperature for both machining methods; It was observed that it reduced cutting force and surface roughness. It was concluded that as the feed rate increased, tool wear, cutting temperature, cutting force, and surface roughness increased. The experimental results showed that feed rate, machining method, and spindle speed affect machining quality. In conclusion, the experimental results significantly impact improving the machining performance of the EAM method.
AtıfScopus1WoS2OpenAlex2İncele - MakaleAçık Erişim2024Scopus SJRQ3Effects of vibration conditions on machinability of aisi 52100 bearing steel
Agar, Salih; Tosun, Nihat; Mahmat, Aybars
This study focused on determining the effects of the cooling condition in the conventional and ultrasonic-assisted turning of AISI 52100 steel. AISI 52100 steel has been widely used in the bearing, mold, and automotive industries because of its superior wear resistance and mechanical properties. However, its high wear resistance caused poor machinability in conventional machining methods. Low surface quality, rapid tool wear, high cutting temperature, and high cutting force are the main difficulties in the conventional machining of AISI 52100 steel. On the other hand, ultrasonic-assisted machining has become widely used in the past decades for the machining of materials that have low machinability in conventional methods. Conventional turning and ultrasonic-assisted turning were selected as machining methods. Ultrasonic-assisted turning experiments were conducted under 20 and 30 kHz vibration frequencies. Cubic Boron Nitride (CBN) cutting tools were used in machining experiments. In machining operations 50, 100, and 150 m/min cutting speeds were selected, and feed rate (0.1 mm/rev) and depth of cut (0.5 mm) were kept constant in experiments. Minimum quantity lubrication technique which used 1% Al2O3 nanoparticle additives cutting fluid and dry cooling methods were used. CBN insert was used as a cutting tool. The effects of cutting speed, cutting method, and cooling condition on surface quality, cutting force, cutting zone temperature, and cutting tool wear were studied experimentally. Analysis of Variance (ANOVA) was carried out to determine the significance of the effects of input variables on process outputs. As a result of this study, it is determined that combined UAT and nanoMQL have significant effects on the process outputs.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2024Scopus SJRQ3ENHANCING MILLING PERFORMANCE OF 6061 ALUMINUM ALLOY WITH NANOCUTTING FLUID AND MQL
Tosun, Nihat; Rasul, Sleman Yahya; Mahmat, Aybars; Tosun, Gul
During the machining of aluminum alloys, the adhesion of chips to the tool affects the performance characteristics. Today, different cooling systems are used to eliminate these negativities. In this study, the effects of end milling using HSS and carbide cutting tools of 6061-T6 aluminum alloy on surface roughness, chip thickness ratio and tool wear were examined using different cooling techniques (dry, minimum quantity lubrication (MQL) and nanocutting fluid). Different cutting speeds (180, 200, 220 m/min) and different feed rates (0.05, 0.06, 0.07 mm/rev) were used in the experiments. According to experimental findings, tool wear and surface roughness decreased at low cutting speed and feed rate by using nanocutting fluid with carbide cutting tools. It has been observed that the chip thickness ratio increases with high cutting speeds using nanocutting fluid and decreases with dry machining and high feed rates. The best milling performance of the aluminum alloy was achieved in experiments using carbide cutting tools and nanocutting fluid.
AtıfScopus4WoS4OpenAlex4İncele - MakaleAçık Erişim2023AISI 52100 Rulman Çeliğinin Ultrasonik Tornalama Yöntemi ile Kesici Takım Ömrünün İncelenmesi
Tosun, Nihat; Mahmat, Aybars; Ağar, Salih
Bu çalışmada, AISI 52100 çeliğinin geleneksel ve ultrasonik tornalanmasında işlem parametrelerinin performans karakteristikleri üzerindeki etkileri yani AISI 52100 çeliğinin işlenebilirliği deneysel, sayısal ve istatistiksel olarak araştırıldı. Çalışmada, işlenebilirliğin tespit edilmesi amacıyla, bağımsız değişkenlerin takım ömrü üzerine olan etkileri belirlendi. Deneysel çalışmalar, 50, 100 ve 150 m/dak kesme hızları, 0.1 mm/devir sabit ilerleme ve 0.5 mm sabit talaş derinliği gibi işleme şartları altında, sementit karbür ve kübik bor nitrür (CBN) kesici takımlar kullanılarak yürütüldü. Ultrasonik tornalamada, kesici takıma iki farklı titreşim genliği (5 ve 10 µm) ve iki farklı titreşim frekansı (20 ve 30 kHz) uygulandı.
- MakaleAçık Erişim2023Scopus SJRQ3EFFECT of the COOLING with AIR and WATER VAPOR on MILLING PERFORMANCES
Mahmat, Aybars; Tosun, Nihat; AǦar, Salih
This study aims to investigate experimentally and analytically the effects of different machining parameters such as cooling methods and cutting tool materials on surface roughness and chip thickness ratio for milling of AA7075-T6 aluminum alloy. The carbide and high-speed steel (HSS) end mills were used as cutting tools and the conventional, vapor, and compressed air were used as cooling methods in the experiments. The experiment conditions for compressed air at the cutting zone were 6 bar pressure and 30 m/s speed flow rate. A mixture of boron oil and water (1/20 mixture ratio) was used as cutting fluid in conventional cooling. The study was carried out using three levels of feed rates (20, 40, 80 mm/min), rotational speeds (780, 1330, 2440 rpm), and a constant 2 mm deep cut. As a result of the experiments, the surface roughness values increased with the increasing levels of feed rate. Besides surface roughness values decreased with increasing levels of the rotational speed. In addition, a better surface quality was obtained in milling processes by using carbide cutting tools compared to HSS tools. It was concluded that the most important parameter affecting the surface roughness and chip thickness ratio is feed rate and the rotational speed, respectively. Better surface roughness and chip thickness ratio were obtained from the vapor processing than the conventional and compressed air.
AtıfScopus2WoS1İncele - MakaleAçık Erişim2020Metalografik Mikroyapı İncelemelerinde Kullanılmak Üzere Çok İstasyonlu Numune Zımparalama ve Parlatma Makinesinin Tasarımı ve İmalatı
Tosun, Nihat; Mahmat, Aybars; Ağar, Salih
Teknolojinin sürekli değişip gelişmesiyle birlikte, birçok alanda yeni makine ve cihazlar insanlığın kullanımına sunulmaktadır. Bu çalışmada, metalografik incelemeler yapmak için, numune hazırlama aşamalarından biri olan ve tam otomatik olarak çalışacak bir numune zımparalama ve parlatma makinesinin tasarımı ve imalatı yapılmıştır. Bu amaçla, daha önceden imal edilmiş numune zımparalama ve parlatma makineleri incelenerek, bu makinelerde görülen eksiklik ve aksaklıklar dikkate alınarak, yeni bir tasarım gerçekleştirilmiştir. Yapılan tasarımda, makinenin otomatik olarak beş farklı istasyonda numuneyi zımpara üzerinde tutan basınç değeri ve zımparalama süresi ayarlanabilmektedir. Beş farklı istasyonda ve her istasyonda arzu edilen tane büyüklüğünde farklı zımparalar yerleştirilmek suretiyle istenilen kalitede numune yüzeyi elde edilecektir.
