Browsing by Publisher "Pleiades Publishing"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
Item Optimizing Optical and Structural Properties of Nanocomposites by ZnO and BP-3(Pleiades Publishing, 2018) Türemiş M.; Keskin I.Ç.; Katı M.I.; Kibar R.; Şirin K.; Çanlı M.; Çorumlu V.; Çetin A.This study aims to find out usage of zinc oxide (ZnO) and 2-hydroxy-4-methoxybenzophenone (BP-3) for getting better optical and structural properties of nanocomposites. Polymer nanocomposites were prepared by adding zinc oxide for minimizing UV rays effects of the sun with the particle size of nanometer in different ratios to a low density polyethylene (LDPE). The polymer mixtures were synthesized by mixing nanocomposite samples with BP-3 featuring UV stabilizer. Besides making tensile testing measurements, in order to find out the optical, structural, mechanical and thermal changes, the new polymer nanocomposites were characterized by XRD, TG-DTA spectra, and SEM images. The samples with zinc oxide which show luminescent properties were examined in terms of radioluminescence features. Radioluminescence spectrum showed characteristic peaks of zinc oxide dispersed nanocomposites prepared with LDPE. The intensity of the characteristic peaks at 530 and 390 nm (exciton) increased by increasing rates of nanopowder zinc oxide while adding BP-3 to the composites caused a decrease in intensity of radioluminescence. © 2018, Pleiades Publishing, Ltd.Item Characterization of Tantalum–Titanium Powders with Universal Powder Bed (UPB) System for Electron Beam Melting Process(Pleiades Publishing, 2020) Ahu Celebi; Gulizia S.; Doblin C.; Fraser D.; Prentice L.Electron beam melting (EBM) is a powder bed fusion additive manufacturing (AM) technique that produces three-dimensional (3D) parts by fusing metallic powders with a high-energy electron beam. Powder has been major issue for the properties of the final parts. Hence, establishing the effect of powder properties on the final product properties is important for producing parts of quality. In this study, Ta–60Ti, Ta–50Ti, Ta–40Ti was a blend of tantalum and titanium powders. The blend of powder was characterized in terms of the particle size distribution (PSD), bulk and tap density, flowability in Hall Funnel flowmeter and particle morphology. In addition, a universal powder bed (UPB) system was used to characterize the powder behavior raking because the UPB system allows a quick assessment of the powder spreading behavior in AM processes. Surface roughness’s of the powder after raking with universal powder bed (UPB) system, the microstructural heterogeneity, defect distributions were investigated. © 2020, Allerton Press, Inc.Item Improvement in Corrosion Resistance of Tantalum Oxide and Tantalum Oxide with Diethanolamine Sol–Gel Coated Magnesium Alloys(Pleiades Publishing, 2022) Gül C.; Albayrak S.; Çinici H.; Aytaç A.Abstract: In this study, corrosion resistance was developed to ensure that AZ91 Mg alloy remains stable in the body for longer periods. For this purpose, tantalum oxide and tantalum oxide with diethanolamine coatings were made by sol–gel method on AZ91 magnesium alloy surfaces. The structural analyses of tantalum oxide and tantalum oxide with diethanolamine obtained by sol–gel method were carried out. By using the dip coating method, coatings with different concentrations of solutions and different dipping numbers were applied on AZ91 Mg alloy surfaces. Thus, the effects of dipping numbers and chemical content of the solution on the coating thicknesses, surface roughnesses, morphologies and corrosion resistances of coating layers were examined. As a result, it was determined that the coating thicknesses increased with the dipping number. The low number of dipping could not provide sufficient protective layer formation on the surface. Better results were obtained in samples with a high dipping numbers. It was observed that needle-like structures were formed in the solution using diethanolamine. As the amount of diethanolamine increased, a more homogeneous and dense coating layer was observed. Accordingly, an increase in corrosion resistance has been observed. It was determined that the corrosion rate of AZ91 Mg alloy has decreased by 86% with increasing dipping number and diethanolamine amount. © 2022, Pleiades Publishing, Ltd.Item 2D/3D Direct Writing of Thermoplastics through Electrohydrodynamic Printing(Pleiades Publishing, 2022) Levent Parali; Koç M.; Yıldız Z.Abstract: This paper describes a novel electro hybrid mechanical system which consists of the following components: electrohydrodynamic printing combined with the fused deposition modeling, electrospinning, and electrospray. The electrohydrodynamic printing section with the fused deposition modeling of the electro hybrid mechanical system was used to obtain fibers from thermoplastics such as polylactic acid, thermoplastic polyurethane, polyethylene terephthalate-glycol, acrylonitrile–butadiene–styrene copolymer, and high impact polystyrene. This study reports the changes in the 2D array and the 3D scaffold structure of the samples and exhibits their characteristics and performance evaluations by comparing them under the same production conditions. © 2022, Pleiades Publishing, Ltd.Item Characterization of a Duplex Coating (Boriding + Hydroxyapatite) on Austenitic Steel(Pleiades Publishing, 2023) Ali Ihsan Bahcepinar; Safiye Ipek Ayvaz; Ibrahim AydinAbstract: In this study, duplex coating process (Boriding + Hydroxyapatite) was applied to 316L stainless steel alloys. Before coating, the substrate materials were shotblasted with 300–500 µm glass beads in a vacuum type shot blast machine. Tribological properties of the alloy with boriding process, its bioactivity and biocompatibility was increased with the hydroxyapatite (HA) coating process. Powder pack boriding technique was used in boriding process and Electrophoretic deposition method (EPD) was used in HA coating process. At the end of the study, the microstructures (SEM), elemental analyzes of the coating surfaces (EDS), Ca/P ratios, coating thicknesses were determined. In addition, the hardness and adhesion qualities of the boride layer were determined. When the results obtained are evaluated, duplex layers were successfully formed for all parameters. © Pleiades Publishing, Ltd. 2023. ISSN 0031-918X, Physics of Metals and Metallography, 2023, Vol. 124, No. 14, pp. 1837–1844. Pleiades Publishing, Ltd., 2023. ISSN 0031-918X, Physics of Metals and Metallography, 2023. Pleiades Publishing, Ltd., 2023.Item Optimal Use of Calcined Boron Waste as a Flux in the Production of Low-Temperature-Sintered Floor Tiles(Pleiades Publishing, 2023) Hakan Cengizler; Koç M.Abstarct: —This study focused on the recycling and optimal use of colemanite waste (CW) in floor tile/tiles (FT) production. Experimental compositions were prepared with various concentrations of CW calcined at 800°C and FT body. The sinterability at low temperatures (1000–1100°C) and the effect of calcined CW on FT properties were investigated. The physical-mechanical properties of the tiles were characterized by linear shrinkage, water absorption and bending strength tests. The microstructure and the phase development of the tiles were determined by SEM-EDX and XRD, respectively. The optimal tile compositions in conformity with the related standards were obtained at 1050°C (30 wt % CW) and 1100°C (5 and 10 wt % CW). The tiles produced with high ratio CW (30 wt %-1050°C) additions had 0.32% water absorption, 5.70% linear shrinkage, and 52.43 MPa bending strength values. The CW calcined at 800°C was favourably used in FT production to lower the sintering temperature with a new possibility to recycle this waste and conserve natural resources. © 2023, Pleiades Publishing, Ltd.Item Effect of Shot Blasting on the Boriding Kinetics of AISI 316L Stainless Steel(Pleiades Publishing, 2023) Ayvaz S.İ.; Aydın İ.; Bahcepınar A.İ.Abstract: In this study, the effect of shot blasting on boriding kinetics of AISI 316L stainless steel alloy was investigated. For this purpose, AISI 316L samples were shot blasted at 6 bar pressure using 300–500 µm glass beads. Shot blasted samples were borided with powder pack boriding technique, using Ekabor 2 boriding powder, with 2, 4 and 6 boriding times at 850, 900 and 950°C boriding temperatures. As a result of boriding, boride layers consisting of FeB and Fe2B phases with a microhardness of ~1497–2135 HV0.1 and an average thickness of ~9.6–49.27 µm were obtained on the surface of AISI 316L stainless steel alloy samples. These boride layers on the AISI 316L stainless steel alloy surface were formed in flat morphology due to the high amount of alloying elements. In the kinetic studies, the activation energy of boron diffusion in AISI 316L stainless steel alloy was calculated as 204.68 kJ mol–1. The obtained results showed that shot blasting decreased the boron diffusion kinetics compared to the results in the literature. © 2023, Pleiades Publishing, Ltd.