Sürdürülebilir Kalkınma Amaçları
Yayınlar
- 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 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