Yazar "Ozarslan, S." seçeneğine göre listele
Listeleniyor 1 - 5 / 5
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Effects of Third-generation LED LCU on Nanomechanical Properties of Orthodontic Adhesives(Polish Acad Sciences Inst Physics, 2017) Bilgic, F.; Altan, H.; Sozer, O. Akinci; Arslanoglu, Z.; Kale, E.; Ozarslan, S.The aim of this study was to compare the hardness and elastic modulus of orthodontic adhesives cured with different light-curing units, based on light-emitting diodes. Standardized samples of orthodontic adhesives, Transbond (TM) XT, Opal (R) Bond (TM) and Light Bond (TM) were prepared in cylinder blocks and cured for three seconds with Valo Ortho LED (Ultradent Products, South Jordan, Utah) and Valo LED High-Power Mode. After grinding and polishing, specimens were stored in distilled water at 37 degrees C for one day. Specimens were investigated using nanoindenter. Employment of Valo Ortho unit has resulted in significantly higher elastic modules for Transbond (TM) XT (p = 0.041). The highest nanohardness and elastic modules were measured for Transbond T XT cured with Valo Ortho (9.47 GPa; 81.85 GPa, respectively) and lowest for Opal (R) Bond (TM) for both Valo Ortho (0.44 GPa; 14.52 GPa, respectively) and Valo High-Power groups (0.44 GPa; 11.84 GPa, respectively).Öğe Fabrication and mechanical characterization of rare earth permanent magnet SmCo5 films(Elsevier Science Sa, 2017) Kuru, M.; Sahin, O.; Ozarslan, S.; Ozmetin, A. E.This study reports mechanical properties of rare earth permanent magnet (REPM) SmCo5 thin films fabricated by RF magnetron sputtering technique. 1 mu m thick SmCo5 thin films were grown on Si (100) substrate at room temperature, and later they were annealed at 400 degrees C. Great care has been taken to decrease O-2 in the chamber throughout deposition. Mechanical and Structural properties of SmCo5 thin films were researched using the nanoindentation and in situ scanning probe microscopy (SPM), Grazing Incident X-ray Diffraction (GIXRD) and Scanning Electron Microscopy (SEM) techniques. Nanoindentation-induced plasticity of SmCo5 thin film was characterized by in situ SPM imaging of indented cross-sections. Nanoindentation results show load-displacement curves are continuous and smooth that there is no pile-up and sink-in behavior. Furthermore, both elastic modulus and nano hardness values of REPM SmCo5 exhibit peak load dependence. Nanohardness increases with increasing indentation test load, while the reduced modulus decrease with increasing indentation test load. The obtained values of the intrinsic nanohardness and intrinsic reduced modulus are 3.47 +/- 0.07 GPa and 43.09 +/- 1.60 GPa, respectively. (C) 2016 Elsevier B.V. All rights reserved.Öğe Influence of CaO on the Nanohardness Behaviour of AZ63 Magnesium Alloys Produced by Mechanical Alloying Method(Polish Acad Sciences Inst Physics, 2016) Boztas, M.; Ozarslan, S.; Sahin, O.In this study we aimed to produce AZ63 magnesium alloys containing different amounts of CaO, to investigate the nanohardness behaviour of the resulting alloys. These alloys were produced by mechanical alloying under argon atmosphere. Magnesium based alloys with the initial CaO content of 0.1%, 0.3%, and 0.5% were produced by high-energy ball milling, followed by process that involved cold pressing and sintering. These alloys were characterized using scanning electron microscopy, scanning probe microscopy, X-ray diffraction, and nanoindentation methods. Unloading segments of nanoindentation curves were analyzed using Oliver-Pharr method. Experimental results show that measured nanohardness exhibits a peak load dependence. As a result, in these alloys the microstructure and nanohardness depend on the content of CaO.Öğe Influence of Rare Earth Element on the Mechanical Properties of ZE41 Magnesium Alloys Produced by Mechanical Alloying(Polish Acad Sciences Inst Physics, 2016) Sahin, O.; Ertsak, F. Haluk; Oztekin, K.; Ozarslan, S.In this work, we have intended to synthesize ZE41 Magnesium alloys having varying content of Ce of 0.3, 0.6 and 0.9 wt.% and to investigate mechanical properties of these alloys. Alloys were produced by mechanical alloying under argon atmosphere. Structural, and mechanical properties of these alloys were investigated by means of XRD, SEM and nanoindenter analysis. From the XRD data it is found that as the Ce content increases, the crystallite size also increases. On the other hand, the hardness of the alloys decreases with the increasing Ce content. Indentation results show that the measured hardness displays a peak load dependence. Load-independent hardness was calculated by Hays-Kendall approach. As a results, it was found that Ce-doping modifies the microstructure and hardness of the alloy.Öğe Nanomechanical Comparison of Commonly Used Dental Crown Cements to a Newly Developed One(Polish Acad Sciences Inst Physics, 2017) Kale, E.; Arslanoglu, Z.; Altan, H.; Bilgic, F.; Tuzlali, M.; Koroglu, A.; Ozarslan, S.The main goal of nanoindentation tests is to obtain elastic modulus and hardness of the specimen material from load-displacement measurements. With this study, it was aimed to establish a quantitative relationship between the nanomechanical properties of commonly used dental cements in comparison to a newly developed crown cement and to predict its performance potential. Nanomechanical properties of polycarboxylate cement (PCC), glass-ionomer cement (GIC), dual-cure self-adhesive cement (SAC) and a newly developed glass-carbomer cement (GCC) were investigated by nanoindentation tests. All samples were fabricated according to their respective manufacturer's instructions. Available damage on the surface due to manipulation was removed by grinding with 1200, 2400 and 4000 grit sandpaper, and then polishing on 6, 3, and 1 mu m diamond-lap-wheel was performed. Nano-mechanical measurements were done using nanoindenter machine with resolution less than 1 nN and displacement resolution of 0.04 nm. Berkovich diamond indenter tip was used for the nanoindentation tests. For each indentation, a set of nanoindentation tests at least on 6 different locations per specimen surface were performed to obtain more representative mean results. Indentation test load-displacement curves were analysed using Oliver-Pharr method, and one-way ANOVA or Kruskal-Wallis test, following Kolmogorov-Smirnov and Shapiro-Wilk, was used to compare the results. Nanohardness (H-nano) values were 0.52 +/- 0.25, 0.45 +/- 0.18, 1.03 +/- 0.82 and 0.43 +/- 0.18 GPa for GIC, GCC, PCC, and SAC, respectively. Reduced elastic modulus (E-r) values were 9.51 +/- 6.17, 11.77 +/- 5.04, 27.37 +/- 20.61, 10.33 +/- 5.08 GPa for GIC, GCC, PCC, and SAC, respectively. There was no statistical difference between the tested materials. PCC was the hardest, and GIC was the least hard material, whereas the newly developed GCC was the second, in terms of H-nano, before SAC. PCC also had the highest Er mean, compared to the other dental crown cements, suggesting lower elastic properties. SAC was more elastic than GCC and less elastic than GIC. GCC had the second highest E-r, standing closer to SAC and GIC. Within the limitations of the current study, it can be concluded that the newly developed glass-carbomer cement is comparable to the other tested commonly used dental crown cements, regarding H-nano and E-r.
