Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Ankara Yıldırım Beyazıt Üniversitesi, Fen Bilimleri Enstitüsü, Türkiye
Tezin Onay Tarihi: 2024
Tezin Dili: İngilizce
Öğrenci: HAKAN ZAFER KIZILKAYA
Asıl Danışman (Eş Danışmanlı Tezler İçin): Kemal Bilen
Eş Danışman: Abdulmecit Güldaş
Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
Özet:
In various areas of the industry, especially in the machining sector, mineral-based boron oil and water mixture is used to prevent cutting tool wear by evacuating the heat generated during cutting, reduce thermal stresses on the workpiece surface, and improve friction at the tool and chip interface. There are studies showing that nano-particles added to fluids improve the thermo-physical properties of the fluids such as density, viscosity, and thermal diffusivity. In this experimental study, nano-fluids were obtained by adding aluminum dioxide (Al2O3), multi-walled carbon nanotube (MWCNT) or titanium dioxide (TiO2) nano-particles at 0.5 percent, 1.0 percent, and 1.5 percent by volume to a low viscosity boron oil and water mixture containing 7 percent boron oil and 93 percent water. The thermo-physical properties of the obtained nano-fluids were measured with various sensors and rheometers. In addition, a turning machining experiment was carried out on Ti-6Al-4V material using these nano-fluids with fixed cutting parameters and the temperature distribution at the tool and chip interface were observed with the help of a thermal camera and the effect of the use of nano-fluids on surface roughness was also measured. As a result of the study, it was observed that increasing the concentration of nano-particles, naturally, continuously increases the density of the nano-fluid at a constant temperature of 24.5 celsius, but this is not the case for dynamic viscosity and thermal diffusivity, and there is a tendency to decrease the properties from 1 percent concentration by volume, which is due to precipitation and sedimentation. Approximately 18 percent temperature reduction was observed when using the nano-fluid containing 0.5 percent MWCNT nano-particles by volume at the cutting tool and workpiece interface. It was also found that values of cutting temperature and surface roughness did not improve with increasing the volume concentration of nano-particles due to precipitation and sediment formation, but on the contrary, deteriorated. With the using of nano-particles at optimum values, an improvement of approximately 25 percent in surface roughness was also detected. As a result, it has been determined that when the volumetric admixtion rate of nano-particles exceeds a certain value, nano-fluids do not provide the desired improvements in machining but they can provide the desired improvements when used at optimum admixtion rates. Keywords: Machining, cutting, boron oil, Al2O3, MWCNT, TiO2, nano-fluid, thermo-physical property, cutting insert, surface temperature, surface roughness.