Yazar "Zengin, Hueseyin" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Evolution of Microstructure, Mechanical Properties, and Corrosion Resistance of Mg-2.2Gd-2.2Zn-0.2Ca (wt%) Alloy by Extrusion at Various Temperatures
    (Mdpi, 2023) Zengin, Hueseyin; Ari, Soner; Turan, Muhammet Emre; Hassel, Achim Walter
    The current investigation involved casting the Mg-2.2Gd-2.2Zn-0.2Ca (wt%) alloy (GZX220) through permanent mold casting, followed by homogenization at 400 degrees C for 24 h and extrusion at 250 degrees C, 300 degrees C, 350 degrees C, and 400 degrees C. Microstructure investigations revealed that alpha-Mg, Mg-Gd, and Mg-Gd-Zn intermetallic phases were present in the as-cast alloy. Following the homogenization treatment, a majority of these intermetallic particles underwent partial dissolution into the matrix phase. alpha-Mg grains exhibited a considerable refinement by extrusion due to dynamic recrystallization (DRX). At low extrusion temperatures, higher basal texture intensities were observed. The mechanical properties were remarkably enhanced after the extrusion process. However, a consistent decline in strength was observed with the rise in extrusion temperature. The corrosion performance of the as-cast GZX220 alloy was reduced by homogenization because of the lack of corrosion barrier effect of secondary phases. A significant enhancement of corrosion resistance was achieved by the extrusion process.
  • Küçük Resim Yok
    Öğe
    Synthesis of Zinc Oxide Nanorods from Zinc Borate Precursor and Characterization of Supercapacitor Properties
    (Mdpi, 2023) Lefdhil, Chikh; Polat, Safa; Zengin, Hueseyin
    The synthesis of zinc oxide (ZnO) was accomplished from zinc borate (Zn3B2O6) minerals to be used as electrodes in supercapacitor applications. The concentrations of obtained zinc (Zn) metal after treatment with hydrochloric acid (HCl) were determined by atomic absorption spectroscopy (AAS). Direct synthesis of ZnO on a nickel (Ni) foam surface was conducted by employing the hydrothermal technique using a solution with the highest Zn content. The results showed the successful synthesis of ZnO nanorods on the surface of Ni foam with an average wall size of approximately 358 nm. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements revealed that the synthesized electrode exhibited battery-type charge storage characteristics, reaching a maximum specific capacitance of approximately 867 mF & BULL;cm-(2) at a current density of 2 mA & BULL;cm-(2). Additionally, the energy and power densities of the electrode at a current density of 2 mA & BULL;cm-(2) were calculated as 19.3 mWh & BULL;cm-(2) and 200 mW & BULL;cm-(2), respectively. These results exhibited promising performance of the single-component electrode, outperforming the existing counterparts reported in the literature.