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Article Citation - WoS: 10Citation - Scopus: 14The Adhesion and Tribological Properties of C-Bn Films Deposited by High Power Impulse Magnetron Sputtering(Elsevier Sci Ltd, 2019) Efeoglu, Ihsan; Totik, Yasar; Keles, Aysenur; Gulten, Gokhan; Ersoy, Kivilcim; Durkaya, GokselNitride based films are very important for industrial applications due to their mechanical and tribological properties. Among the nitride based films, c-BN films have superior properties. But, the adhesion properties of c-BN films deposited using magnetron sputtering with different power sources are inadequate generally. Recently, High Power Impulse Magnetron Sputtering (HiPIMS) power sources have been used to increase the adhesion of coatings and there is no open literature about c-BN deposited using HiPIMS. From this point, c-BN films were coated on 4140 steels using HiPIMS with closed-field unbalanced magnetron sputtering (CFUBMS). In the process, two B4C, two Ti targets and Ar + N-2 gas mixture were used to synthesize c-BN films. The amount of N-2 was altered as 2.5, 3.5 and 4.5sccm. The characteristic properties of c-BN films were analyzed using SEM, XRD and FT-IR. The mechanical properties were tested using a microhardness and scratch testers. The tribological properties were performed by a pin-on-disc tribotester under atmosphere, argon, and oil test conditions. The results showed that the properties of c-BN films deposited by HiPIMS are interesting. The hardness values were obtained above 36 GPa and the maximum critical load was reached to 80 N. Also, the minimum CoFs were observed as expected from the oil condition, in that case, the lowest CoF (mu congruent to 0.06) was noted from the hardest coating.Article Citation - WoS: 8Citation - Scopus: 8Experimental Investigation of Friction in Deep Drawing(Springer London Ltd, 2017) Kalkan, Hakan; Hacaloglu, Tugce; Kaftanoglu, BilginInvestigation of friction is carried out in the radial drawing region between the die and blank holder and also in the stretching zone over the punch in deep drawing. Two methods are developed to calculate the coefficient of friction in each zone using the experimentally determined data such as punch force diagrams and strain distributions obtained by an optical scanning system. The current methods differ from the existing techniques which are obtained in simulative tests. The proposed methods can be applied in room temperature and at elevated temperatures. Comparisons of friction coefficients are made with those obtained by other techniques.Article Citation - WoS: 3Citation - Scopus: 4Friction and Wear Behavior of Selected Dental Ceramics(World Scientific Publ Co Pte Ltd, 2009) Park, Jongee; Pekkan, Gurel; Ozturk, AbdullahThe purpose of this study was to determine the friction coefficients and wear rates of six commercially available dental ceramics including IPS Empress 2 (E2), Cergo Pressable Ceramic (CPC), Cercon Ceram (CCS) and Super porcelain EX-3 (SPE). Bovine enamel (BE) was also tested as a reference material for comparison purposes. Samples of the dental ceramics were prepared according to the instructions described by the manufacturers in disk-shape with nominal dimensions of 12 mm x 2 mm. The wear tests were performed by means of a pin-on-disk type tribometer. The friction coefficients and specific wear rates of the materials were determined at a load of 10 N and rotating speed of 0.25 cm/s without lubrication. Surface morphology of the wear tracks was examined using a scanning electron microscope. Statistical analyses were made using one-way ANOVA and Turkey's HSD (P < 0.05).Conference Object Citation - Scopus: 42d Fe Modelling of Machining: a Comparison of Different Approaches With Experiments(2005) Bil,H.; Tekkaya,A.E.; Kiliç,S.E.[No abstract available]Article Citation - WoS: 11Citation - Scopus: 13Evaluating porthole and seamless aluminum tubes and lubricants for hydroforming(Springer London Ltd, 2015) Kaya, SerhatThe effect of extrusion method and lubrication on formability of aluminum tubes in hydroforming is experimentally investigated. First, the formability differences between seamless and porthole aluminum 6063 and 6260 alloy tubes, at T1 and T6 heat treatment conditions, are studied using free bulging. Second, the performances of a wide range of lubricants are ranked using zone-dependent friction tests, e.g., guiding zone and expansion zone, which emulate the two different interface mechanics existing in a THF operation. Results showed that seamless tubes, under any condition, give 5 % more expansion compared to porthole. Also, if a tube has T6 condition, seamless shows clear formability advantage over porthole. However, porthole is found to be quite satisfactory for tubes at T1 condition since they achieved more than % 10 expansion. "Zone-dependent" (expansion zone and guiding zone) lubrication tests are conducted using wet and dry lubricants. Results showed that while a dry lubricant performed best in the expansion zone, a wet lubricant performed best in the guiding zone.Article Citation - Scopus: 20Investigation of the Tribological Behaviour of Electrocodeposited Ni-Mos2 Composite Coatings(Inderscience Publishers, 2017) Güler,E.S.; Konca,E.; Karakaya,I.Composite electroplating of solid lubricants in a metal matrix is an effective way to lower coefficient of friction (COF) and improve wear resistance of surfaces in sliding contact. In this work, Ni-MoS2 composite coatings were deposited on AISI 304 stainless steel substrates by electroplating from Watts bath containing suspended MoS2 particles and their tribological behaviour was studied. The effects of MoS2 particle concentration (5, 10 and 30 g/l), MoS2 particle size (1.440 and 5.156 μm), pH (2, 3 and 4), current density (3.8, 4.8 and 5.8 A/dm2) and the surfactant (sodium lignosulfonate, SLS) concentration (0.3 and 1 g/l) on the tribological behaviour were investigated using a ball-on-disc tribometer at ambient conditions. Lower current density, smaller particle size and higher concentration of MoS2 decreased COF. While increasing the surfactant concentration decreased the COF, its friction lowering effect was much more pronounced at relatively lower concentrations of MoS2 in the electrolyte. Copyright © 2017 Inderscience Enterprises Ltd.
