Browsing by Author "Korkmaz, Seyma"

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Citation - WoS: 2
Citation - Scopus: 2
Investigation of Tribological Performances of Ep Oil Additive With Gelatin and Pva Coated Nanoparticles
(Gazi Univ, Fac Engineering Architecture, 2023) Abushrenta, Hamza Mohamed S.; Kabave Kılınçarslan, Sena; Korkmaz, Seyma; Şirvan, Onur Can; Çetin, M. Hüseyin
In this study, the effect of the lubricant prepared by adding EP and silver nanoparticles (AgNP) coated with different ligands to the ethylene glycol (EG) liquid on the tribological performance of the bearing material made of CuSn10Zn tin bronze was investigated. For the tribological analysis of EP additive, the optimum EP ratio was determined by carrying out wear tests in dry medium, pure EG and lubricant media prepared by adding volume of 5%, 10%, 15% EP to EG liquid. Optimum AgNP concentration and ligand material were determined by using volume of 2%, 5% and 8% AgNP coated with different ligands together with the determined optimum EP. In both stages, where optimum EP and AgNP concentrations were determined, the experiments were carried out with a reciprocating tribometer (ball on plate) with a load of 20 N and a speed of 40 rpm. Experiment results were analyzed by comparing friction coefficient, wear volume values with SEM and 3D topography images. According to the analysis results, it was determined that the friction coefficient and wear volume values obtained in EG + 5% EP environment were lower than 10% and 15% concentrations. According to the results obtained from the interaction of EG + 5% EP with AgNP, the optimum AgNP concentration was determined as 2%, and the optimum ligand material was determined as gelatin (Gel). In EG + 5% EP + 2% AgNP_Gel conditions, the friction coefficient was reduced by 18.70% and the volume loss by 16.94% compared to EG.
Citation - WoS: 1
Citation - Scopus: 2
Investigation of Wear and Corrosion Resistance of Wc-Coated Pearlitic Railway Steel in Dry and Wet Conditions
(Elsevier Sci Ltd, 2025) Orak, Abdulkadir; Korkmaz, Seyma; Cetin, M. Huseyin
In this study, the effect of WC coating on the tribological performance of R260 rail steel was investigated by roller-on-plate wear tests and potentiodynamic polarisation corrosion tests carried out in dry and pure water environments. The High-Velocity Oxygen-Fuel (HVOF) method was used for the coating process. The tests were conducted with a weight of 40 N and a sliding speed of 0.03 m/s. An Ag/AgCl reference electrode was also used for corrosion tests in a 3.5 % NaCl solution. To produce cyclic polarisation curves, the experiments were carried out at a scan rate of 1 mV/s within a potential range of +/- 0.25 V. The effect of WC coating on the wear performance of rail steels was analysed quantitatively with the friction coefficient and volume loss parameters and visually with SEM and 2D-3D topography images. The effect of the coating on the corrosion performance was evaluated numerically with the corrosion potential, corrosion current intensity, and corrosion rate values, as well as elementally and visually with SEM and EDX images. Wear test results showed that the wear volume in WCcoated rail steels decreased by 43.07 % and 46.94 % compared to uncoated rail steels in dry and wet conditions. Corrosion test results showed that the corrosion rate of WC-coated rail steels was lower compared to uncoated rail steels, and the corrosive effect spread to a smaller area.