Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ2Investigation of radiation shielding parameters of AZ61 magnesium alloy after electric arc spray and micro arc oxidation processes
Durna, İdris; Yılmaz, Demet; Çatar, Recep; Altun, Hikmet
In this study, the radiation shielding parameters of AZ61 magnesium (Mg) alloy, which is used in automotive, aerospace, and biomedical fields due to its low density, high specific strength, and biocompatible properties, were determined to investigate its usability in nuclear protection applications. Firstly, Al coating was applied to AZ61 Mg alloy by electric arc spray process and then ceramic oxide layer was obtained by micro arc oxidation (MAO) method. Then, the radiation shielding properties of AZ61 alloy were investigated. The radiation shielding parameters such as mass attenuation coefficient (MAC), mean free path (MFP), half-value layer (HVL) and effective atomic numbers (Zeff) were measured in gamma spectrometer with Ba-133 radioactive sources. The fast neutron removal cross-sections (ΣR), exposure buildup factors (EBF) were theoretically determined. The results revealed that the duplex coating (AZ61-Al-O) significantly enhanced the gamma shielding capability compared to the uncoated AZ61 alloy, achieving about 8.0 % higher MAC at 383.8 keV. Therefore, the AZ61-Al-O sample can be considered a promising lightweight material for radiation protection applications.
AtıfScopus3WoS3OpenAlex4
İncele - MakaleYalnız künye2026Scopus SJRQ2Effect of Scandium Addition on Recycled A356 Alloy: Experimental Investigation and CALPHAD-Based Thermodynamic Analysis
Kutsal, Ümit; Barutçuoğlu, Burak; Sağnak, Yiğit; Toker, Abidin; Çatar, Recep; Çolak, Murat
This study systematically investigates the influence of scandium (Sc) additions at 0.1, 0.2, and 0.3 wt.% on the melt quality, microstructural characteristics, fluidity, and mechanical performance of A356 aluminum alloy under recycling-oriented casting conditions. The alloy charge consisted of 20% primary aluminum and 80% recycled scrap, while the Fe content was maintained at 0.2 wt.%. Melt treatment was performed by rotary degassing using a commercial flux. Melt quality was assessed using the Reduced Pressure Test (RPT) and bifilm index analysis, whereas casting performance was evaluated through an eight-channel fluidity test. Mechanical behavior was characterized by tensile and Brinell hardness testing, and microstructural and phase analyses were conducted using scanning electron microscopy (SEM) and X-ray diffraction (XRD). To complement the experimental investigation and provide a thermodynamic basis for interpretation, phase stability, solidification behavior, and phase-fraction evolution were examined using Thermo-Calc within the CALPHAD framework. By combining experimental characterization with computational thermodynamic analysis, this study elucidates the effect of Sc content on the processing–microstructure–property relationships of recycled A356 alloys and provides a systematic basis for evaluating Sc modification in high-recycled-content aluminum castings.
- MakaleAçık Erişim2025Scopus SJRQ2Investigation of the Structural and Corrosion Properties of Duplex Surface Treated AZ31 Magnesium Alloy
Durna, İdris; Çatar, Recep; Altun, Hikmet
The AZ31 alloy was first completely coated with pure aluminum in this study using the electric arc spray coating method. Then, considering the existing benefits of the micro-arc oxidation process (MAO), a ceramic oxide coating was formed by applying MAO to the Al-coated surface. Thus, a duplex coating was obtained on the base material. The structural properties of both the Al-coated samples and the duplex coatings obtained after the MAO process were investigated by scanning electron microscopy, energy-dispersive x-ray analysis (EDS), and x-ray diffraction devices. The electrochemical behavior of the coatings was carried out in a 3.5 wt.% NaCl solution. The samples were polarized from the potential value − 0.2 V below the corrosion potential to the maximum value of 2 V at a scanning rate of 1 mV/s, and potentiodynamic polarization curves were recorded. According to the electrochemical experiments, Al coatings and duplex coatings improved the corrosion resistance of AZ31 alloy. The corrosion current density values were 298.23 µA/cm2 for the base material, 0.415 µA/cm2 for the Al coating, and 0.014 µA/cm2 for the duplex coating, respectively. The best corrosion resistance among all samples was obtained in duplex-coated samples obtained by MAO. Due to their low corrosion resistance, magnesium alloys are restricted in many areas, especially aviation, automotive, and biomedical. Therefore, this study aimed to improve the corrosion resistance of AZ31 magnesium alloy.
- MakaleAçık Erişim2025Scopus SJRQ4Effect of Plasma Electrolytic Oxidation Process on Corrosion Resistance of Al-Coated AZ61 Magnesium Alloy
Durna, İdris; Çatar, Recep; Altun, Hikmet
Magnesium alloys are extensively utilized in aerospace, aviation, and automotive sectors due to their low density and high specific strength, which offer significant advantages for lightweight structural applications. Their low density especially directs the attention of the aviation sector, where lightness is necessary, to these alloys. However, one of the disadvantages that restricts their use in the industry is their low corrosion resistance. In this study, the Plasma Electrolytic Oxidation (PEO) process was applied in a silicate-based electrolyte to AZ61 magnesium alloy pre-coated with aluminum using the electric arc spraying technique. To examine the characteristics of the fabricated coatings, their phase structures, surface features, and elemental compositions were investigated through XRD, SEM, and EDS analyses. Corrosion performances of coatings were investigated by potentiodynamic polarization test in 3.5% NaCl solution. As a result of electrochemical tests, corrosion current density values for the base sample (AZ61) and PEO coating (AZ61-PEO) were determined as 36,29 μA. cm−2 and 6,53 μA. cm−2, respectively. The findings highlight that the Al₂O₃ layer formed following PEO treatment significantly enhanced the corrosion resistance compared to the base sample.
