Sürdürülebilir Kalkınma Amaçları
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- MakaleYalnız künye2025Scopus SJRQ1First exploration of Pr6O11 nanoparticle integration in borotellurite glasses: Synthesis, characterization, and performance for enhanced mechanical strength and radiation shielding
Kilic, G.; Ilik, E.; Kavaz, E.; Durmus, Hasan; Güler, Ömer; Birdogan, Selcuk; ALMisned, Ghada; Tekin, H.O.
This study investigates the incorporation of Pr6O11 nanoparticles into lithium borotellurite glass matrices to enhance their mechanical and radiation shielding properties. Glass compositions, synthesized with varying Pr6O11 concentrations from 0 to 8 mol%, exhibited increasing densities from 4.00783 g cm−3 to 4.94440 g cm−3 and reduced molar volumes, confirming nanoparticle-induced densification. X-ray diffraction analysis revealed amorphous structures with shifts in the hollow band indicating compact network rearrangements. Scanning electron microscopy and energy-dispersive X-ray analyses confirmed homogeneous Pr distribution up to 6 mol%, with clustering observed in 8 mol% samples. Vickers’ microhardness values progressively increased, highlighting enhanced mechanical strength due to reduced non-bridging oxygen ions and network cross-linking. Gamma-ray shielding experiments demonstrated superior performance of the 8 mol% sample (Pr8), with the highest mass attenuation coefficients, effective atomic number, and reduced half-value layer. Neutron attenuation assessments further confirmed improved shielding capabilities, with Pr8 achieving the highest effective removal cross-section. In conclusion, Pr6O11-doped lithium borotellurite glasses demonstrate significant potential for advanced radiation shielding applications.
AtıfScopus10OpenAlex11
İncele - DüzeltmeYayıncıda açık erişim2025Scopus SJRQ1Corrigendum to “A short review of structural, mechanical and magnetic properties of high and medium entropy alloys added rare earth elements” [Mater. Today Commun. 47 (2025) 113264] (Materials Today Communications (2025) 47, (S2352492825017763), (10.1016/j.mtcomm.2025.113264))
Yayla, Nihal; Güler, Ömer
The authors regret that in the published version of the article, although the explanations for Figs. 13–16 (Also, Figure numbers and explanations given just below the figures) are correct in the text, the figure numbers in text are mixed up. The incorrect figure title and its correction are as follows: On page 9, throughout the text: - All sentences starting with Fig. 14 (Wrong) has been corrected to Fig. 13.- All sentences starting with Fig. 15 (Wrong) has been corrected to Fig. 14.- All sentences starting with Fig. 16 (Wrong) has been corrected to Fig. 15.On page 10, throughout the text: - All sentences starting with Fig. 13 (Wrong) has been corrected to Fig. 16.The authors would like to apologise for any inconvenience caused.
AtıfScopus1İncele - MakaleYalnız künye2025Scopus SJRQ2Effects of Trace Rare Earth (TRE) additions on thermal, crystal structure, and radiation shielding properties of CuAlMn high-temperature S-M alloys: A closer look at Cerium effect
Kalay, Ece; Özkul, İskender; Karaduman, Oktay; Kızılgün, Yasin; Güler, Ömer; Canbay, Canan Aksu; Kilic, G.; Baykal, Duygu Sen; ALMisned, Ghada; Tekin, H.O.
This study systematically investigates the effect of Ce addition on the thermal, structural, and radiation shielding properties of CuAlMn-based high-temperature shape memory alloys (HTSMAs). Among the different compositions, Ce-III demonstrated the most balanced performance, exhibiting optimized phase transformation behavior, microstructural refinement, and enhanced gamma-ray attenuation. Differential Scanning Calorimetry (DSC) analysis revealed that Ce-III exhibited lower transformation temperatures, with austenite start (As) and finish (Af) temperatures of 378.13 °C and 429.75 °C, respectively, and martensite start (Ms) and finish (Mf) temperatures of 402.52 °C and 341.91 °C, suggesting improved thermal stability. Microstructural analysis indicated significant grain refinement, attributed to Ce's dislocation pinning effect, which contributed to enhanced strength and radiation attenuation. X-ray diffraction (XRD) patterns confirmed the formation of Ce-rich intermetallic phases, such as Mn1.15Cu3.85Ce and Cu8Ce4, which increased density and photon interaction probability. The Ce-III alloy exhibited superior linear attenuation coefficients and reduced half-value layer, reinforcing its effectiveness as a radiation shielding material. It can be concluded that Ce-III represents an optimal composition with a synergistic combination of structural stability, phase transformation control, and enhanced radiation shielding capabilities, making it a promising candidate for nuclear and high-radiation applications.
AtıfOpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ2Multifunctional properties and microstructural correlations of NiCoMnTi-Based high entropy alloys with focus on magnetic, thermodynamic, and radiation shielding characteristics
Özkul, İskender; Karaduman, Oktay; Şimşek, Tuncay; Şimşek, Telem; Canbay, Canan Aksu; Güler, Ömer; ALMisned, Ghada; Baykal, Duygu Sen; Tekin, Huseyin Ozan
High-entropy alloys (HEAs) are a novel class of materials known for their complex compositions and exceptional multifunctional properties. In this study, NiCoMnTi-based HEAs were modified with Fe, Cr, and Cu as fifth elements to systematically investigate their structural, magnetic, thermodynamic, and nuclear radiation shielding characteristics. The alloys were synthesized via arc melting and characterized using XRD, SEM-EDS, VSM, and theoretical modeling methods. The findings reveal that each additional element uniquely alters the alloy’s properties. The Fe-containing alloy exhibited a well-defined lamellar microstructure, the highest saturation magnetization (10.79 emu/g), and a Curie temperature near 450 K, along with strong gamma-ray shielding performance across both low and high energy ranges. The Cr-containing alloy demonstrated soft magnetic behavior, featuring the lowest coercivity (29.64 Oe) and the highest fast neutron removal cross-section. In contrast, the Cu-containing alloy enhanced low-energy photon attenuation due to its higher atomic number but exhibited limited magnetic homogeneity. Despite these differences, all samples displayed stable thermodynamic behavior and comparable buildup factor trends. Overall, the addition of Fe led to a synergistic improvement in both magnetic and radiation shielding capabilities of the NiCoMnTi-based HEA system.
AtıfScopus3OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ2Comprehensive evaluation of thermal, structural, magnetic, and radiation shielding properties of CuAlNi and CuAlNi-X (X = Co, CoFe, CoFeMn, CoFeMnCr) high-temperature shape memory alloys
Özkul, İskender; Karaduman, Oktay; Şimşek, Telem; Şimşek, Tuncay; Canbay, Canan Aksu; Güler, Ömer; Şan, Mert Hüseyin; ALMisned, Ghada; Tekin, H.O.
This study investigates the thermal, structural, magnetic, and radiation shielding properties of CuAlNi-based high-temperature shape memory alloys (HTSMAs) enhanced through sequential alloying with Co, Fe, Mn, and Cr. Five different variants were produced, designated as CRef (reference CuAlNi alloy), CCo (CuAlNiCo), CFe (CuAlNiCoFe), CMn (CuAlNiCoFeMn), and CCr (CuAlNiCoFeMnCr). Differential scanning calorimetry (DSC) confirmed the presence of reversible martensitic transformations in all alloys, with Co and Mn additions significantly enhancing thermal stability. Structural analyses using X-ray diffraction (XRD) and microscopy showed significant grain refinement and phase transitions, while magnetic measurements highlighted the strong ferromagnetic response of CCo (CuAlNiCo) and the increased coercivity of CMn (CuAlNiCoFeMn) due to domain-pinning effects. Moreover, radiation shielding analyses demonstrated the critical influence of density and elemental composition, with CRef exhibiting superior linear attenuation coefficients (LAC), effective atomic number (Zeff), and energy absorption buildup factor (EBF) performance, attributed to its optimized Cu fraction and high density (7.1296 g/cm3). In contrast, CMn (CuAlNiCoFeMn) showed the weakest shielding properties due to reduced density and Mn content. Among the samples, CRef emerged as the superior alloy, demonstrating exceptional multifunctionality across all evaluated parameters, while CCr (CuAlNiCoFeMnCr) displayed synergistic properties, combining shape memory behavior with competitive shielding efficiency. It can be concluded that CuAlNi-based HTSMAs hold significant potential as multifunctional materials, particularly for nuclear safety and aerospace engineering applications, where adaptive functionality and radiation protection are critical.
AtıfScopus2OpenAlex2İncele - Derleme MakaleYalnız künye2025Scopus SJRQ1A short review of structural, mechanical and magnetic properties of high and medium entropy alloys added rare earth elements
Yayla, Nihal; Güler, Ömer
This study presents a comprehensive review of the structural, mechanical and magnetic properties of high and medium entropy alloys (HEA and MEA) with rare earth elements (REE) additions. The addition of REE has been shown to have significant effects on phase transformations, microstructural arrangements and thermodynamic stability. Studies in the literature show that REE addition improves properties such as hardness, strength, deformation resistance and magnetic performance. In particular, changes such as transitions from FCC to HCP, formation of intermetallic phases and grain refinement have been observed in phase types with the addition of elements such as Gd, Y and Nd. REE added HEAs offer great potential for modern engineering and advanced technology applications with their superior magnetic moments, magnetocaloric effects and thermal stability. However, there is limited information in the literature on REE added HEAs. This review aims to provide a comprehensive framework for the development of REE added HEAs and to serve as an important reference point for future research.
AtıfScopus7WoS7OpenAlex6İncele - MakaleAçık Erişim2025Scopus SJRQ1Examining the trade-off between structural, mechanical properties and shielding performance of Pr2O3-enhanced 316L stainless steel
Yayla, Nihal; Albayrak, M.Gökhan; Güler, Ömer; Baykal, Duygu Sen; Alkarrani, Hessa; ALMisned, Ghada; Zakaly, Hesham M.H.; Tekin, H.O.
This study explores the structural, mechanical, and radiation shielding properties of 316L stainless steel composites reinforced with varying weight percentages of Pr2O3. The aim is to enhance radiation attenuation capabilities while maintaining structural integrity for nuclear applications. The composites were fabricated using the mechanical alloying method, followed by detailed characterization through X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Key radiation shielding parameters, including mass attenuation coefficient, linear attenuation coefficient, half-value layer, and effective atomic number, and transmission factor values were analysed using theoretical and computational models. Additionally, elastic modulus calculations were performed to assess mechanical properties. The results indicate that incorporating Pr2O3 significantly enhances shielding performance. The 316L-SS%20Pr2O3 composite exhibited the highest mass and linear attenuation coefficients values, with a notable reduction in half value layer values compared to the unreinforced 316L stainless steel. At lower photon energies, effective atomic number improved by 39.3 % for the 316L-SS%20Pr2O3 sample, while neutron shielding efficiency also increased. However, the elastic modulus decreased with higher Pr2O3 content, reflecting a trade-off between mechanical stiffness and radiation shielding efficiency. The findings demonstrate that 316L-SS%20Pr2O3 is a promising material for applications requiring superior radiation shielding, particularly in environments where mechanical load is secondary.
AtıfScopus8OpenAlex8İncele - MakaleYalnız künye2024Scopus SJRQ1The effect of high entropy oxide on radiation shielding parameters of erbium oxide doped glasses
Kanca, M. Sait; Taşgın, Yahya; Yılmaz, Demet; Pathman, Abdul Fatah; Güler, Ömer
High-entropy materials are one of the most studied topics in recent years due to the extraordinary properties they exhibit. High entropy oxide (HEO) is a group of materials that have been studied for different applications. However, the effects of HEOs on the radiation properties of glasses are not well known. In this study, the structural, radiation and neutron shielding properties of SiO2 glass systems doped erbium oxide reinforced with refractory high entropy oxide (RHEO) with the formula TiMoNbTaWZrO11 were investigated. RHEAs used in the study were produced and characterized in our laboratory. Then, they were added to the glass samples at different rates together with Erbium oxide. As a result of SEM-EDS and XRD analyses, it was determined that the additives were distributed very homogeneously on the glass. The composition of glass systems is [95SiO2+(5-x)Er2O3+x TiMoNbTaWZrO11], where (x = 0, 0.5, 1 and 2 %, mol). The linear and mass attenuation coefficients (LAC and MAC), mean free path (MFP), half-value layer (HVL) and effective atomic numbers (Zeff) and effective electron density (Nel) of the glass structures were experimentally measured at the energy region of 53.16–661.62 keV. Also, the equivalent dose rates due to fast neutrons absorption were measured by using an 241Am–Be fast neutron source. Exposure buildup factor (EBF) and fast neutron removal cross section (ΣR) were theoretically determined. The proton and alpha shielding parameters of glasses were calculated. It is observed that glasses containing higher amounts of refractory high entropy oxide, within the SiO2–Er2O3 composition, demonstrated enhanced capabilities for shielding against radiation and neutrons.
AtıfScopus15WoS15OpenAlex17İncele - MakaleYalnız künye2024Scopus SJRQ2Activity of nanosized copper-boron alloys against Phytophthora species
Yiğit, Uğur; Türkkan, Muharrem; İlhan, Hasan; Şimşek, Tuncay; Güler, Ömer; Derviş, Sibel
This study aimed to evaluate the antifungal activity of copper-boron (Cu-B) nanoalloys against a range of Phytophthora species, including P. capsici, P. citrophthora, P. palmivora, P. cinnamomi, P. nicotianae, P. cactorum, P. plurivora, P. inundata, and P. megasperma. The nanoalloys were synthesized via mechanical alloying under an argon atmosphere, resulting in the formation of nanocrystalline Cu-B nanoalloys with irregular morphology and particle sizes ranging from 50 to 240 nm. At a concentration of 250 µg mL−1, the Cu-B nanoalloys demonstrated complete inhibition of mycelial growth, sporangium production, and zoospore germination in all tested Phytophthora species. The EC50 values for mycelial growth ranged from 28.02 to 120.17 µg mL−1, while for sporangium production and zoospore germination, they were below 10 µg mL−1. Furthermore, the nanoalloys exhibited fungicidal activity against specific Phytophthora species, such as P. capsici, P. citrophthora, P. inundata, and P. megasperma, at concentrations of 100, 250, 250, and 250 µg mL−1, respectively. Notably, the Cu-B nanoalloys displayed significant protective and curative effects on tuber rot severity in P. nicotianae-inoculated potatoes, resulting in reductions of 94.13% and 92.61% compared to the control, respectively, at a concentration of 10 µg mL−1 (P < 0.05). These findings highlight the potential of Cu-B nanoalloys as a promising fungicide for the management of plant diseases caused by Phytophthora spp.
AtıfScopus3WoS1OpenAlex2İncele - MakaleAçık Erişim2024Scopus SJRQ2Zr and V-doped effect on Martensitic transformations and magnetic properties of NiMnIn shape memory alloy
Taşgın, Yahya; Kanca, M. Sait; Kök, Mediha; Öner, Ecem Özen; Güler, Ömer
In this study, the elements vanadium (V) and zirconium (Zr) were doped separately as a fourth element to the ternary NiMnIn Heusler magnetic shape memory alloy and the alloys were produced as ingots by arc-melting method. The shape memory properties, microstructures, magnetic and microstructural changes of these new alloys were investigated in detail. The vanadium (V) and zirconium (Zr) elements doped into the alloy caused a decrease in the transformation temperature values of the alloy, but did not cause a significant change in its magnetic properties. The master sample, which has low hysteresis, undergoes a phase transition from the martensite phase to the austenite phase due to an increase in the nucleation of austenite phases at the twinning boundaries. Here, the vanadium and zirconium doping of the alloy caused an increase in the strength and ductility values of the alloy and this caused the formation of the second phase. Due to the increase of this phase formation in the alloy, it can be said that there is a slight decrease in the shape retention of the alloy.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2On β-titanium alloys: tailoring gamma-ray, and neutron transmission properties for nuclear and biomedical applications
Almisned, Ghada; Baykal, Duygu Sen; Alkarrani, Hessa; Güler, Ömer; Kilic, Gokhan; Mesbahi, Asghar; Tekin, Huseyin Ozan
This study explores the gamma-ray and neutron transmission properties of β-Titanium alloys pivotal for their performance in nuclear and biomedical applications. Utilizing the Monte Carlo N-Particle (MCNP 6.3) simulations, we analyzed a spectrum of Ti-based alloys modified with elements like molybdenum (Mo), zirconium (Zr), niobium (Nb), and hafnium (Hf) to determine their radiation attenuation properties. Key parameters such as mass and linear attenuation coefficients, half-value layers, exposure buildup factors, and fast neutron effective removal cross-section values were computed, revealing significant enhancements in attenuation with the addition of high-Z elements. Specifically, alloys like Ti50Hf50 and (TiZr)40Cu60 exhibited superior photon and fast neutron attenuation due to their high-Z constituents. For instance, Ti50Hf50 showed a mass attenuation coefficient of 0.217 cm2/g and a half-value layer of 2.97-cm at 0.1 MeV photon energy, while (TiZr)40Cu60 demonstrated similar performance with a mass attenuation coefficient of 0.198 cm2/g and a half-value layer of 3.26-cm. These alloys also exhibited effective neutron removal cross-section values of 0.115 cm-1 and 0.130 cm-1, respectively. Alloys with lower-Z elements showed less attenuation, which may be beneficial in scenarios requiring reduced radiographic contrast in biomedical applications. The MCNP outcomes were in strong agreement with standard data, affirming the accuracy of computational methods in predicting material behavior. In conclusion, tailored alloy development is crucial for improving radiation shielding and diagnostic visualization, with broader implications for patient safety and treatment efficacy.
AtıfScopus3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ1Radiation shielding properties of composites of TiZrNbHfTa refractory high entropy alloy reinforced with TiZrNbHfTaOx high-entropy oxide
Güler, Ömer; Yılmaz, Demet; Kanca, M. Sait; Edalati, Kaveh; Taşgın, Yahya
Radiation shielding materials play a critical role in advancing the next generation of nuclear reactors. Among these, high-entropy materials with refractory properties emerge as a new category for radiation shielding applications. This study introduces TiZrNbHfTa-TiZrNbHfTaOx composites tailored for such purposes. Initially, a TiZrNbHfTa refractory high-entropy alloy (RHEA) is synthesized via mechanical alloying, followed by the oxidation of the alloy to obtain its refractory high-entropy oxide (RHEO), TiZrNbHfTaOx. Composites are then prepared by blending 5%, 10%, and 20% weight fractions of RHEO with RHEA using mechanical alloying. Comparative analysis of shielding properties reveals a decrease in mass attenuation coefficient and effective atomic number with increasing RHEO content. While RHEA exhibits superior shielding performance against gamma photons and neutrons, the composite containing 20% RHEO emerges as the optimal shield against alpha and proton irradiations. The equivalent neutron dose rate and removal cross-section values are obtained 49.8% and 0.142 for the composite with 20% RHEO, respectively. These findings, supported by computational simulations in this study, contribute valuable insights for the advancement of novel shielding materials crucial for future nuclear reactor technologies.
AtıfScopus24WoS22OpenAlex24İncele - MakaleAçık Erişim2024Scopus SJRQ1Fabrication and structural, physical, and nuclear radiation shielding properties for Oxide Dispersion-Strengthened (ODS) alloys through Erbium (III) oxide, Samarium (III) oxide, and Praseodymium (III) oxide into 316L matrix
Güler, Seval Hale; Güler, Ömer; Kavaz, E.; ALMisned, Ghada; Albayrak, M. Gökhan; Issa, Bashar; Tekin, H.O.
We report a comprehensive investigation on customization process of Oxide Dispersion-Strengthened alloys through Sm2O3, Pr2O3, and Er2O3 incorporation into 316L stainless steel matrix in terms of a desired enhancement in structural, physical, and nuclear radiation shielding properties. Oxide powders are incorporated into 316L stainless steel powder all with the same purity of 99.5%. These were Erbium oxide (Er2O3), Praseodymium oxide (Pr2O3), and Samarium oxide (Sm2O3). First, X-Ray diffraction and Scanning Electron Microscope/Energy-dispersive X-ray spectroscopy analyses are conducted in order to investigate their physical and structural properties. Next, two different experimental setups are employed using a133Ba and 241Am/Be sources for the measurements of gamma-ray and neutron transmission properties of Oxide Dispersion-Strengthened alloys. The maximum density increment is achieved through Er2O3 compared to other reinforced oxides. The detector counting value reached its minimum level when a 5% Er2O3 oxide dispersion was introduced into the 316L SS matrix. Similarly, the most significant degree of photon absorption, the highest values of mass attenuation coefficient, lowest half value layer, and most effective atomic number, were all attained by the same sample. Based on the findings derived from the investigation, it can be concluded that incorporating Er2O3 oxide into 316L steel can be considered as a viable option in terms of enhancing the critical properties of Oxide Dispersion-Strengthened alloys for extreme conditions such as nuclear reactors and other similar fields, where the behavioral attributes of the utilized materials are at utmost importance.
AtıfScopus22OpenAlex25İncele - MakaleYalnız künye2024Scopus SJRQ1A closer-look on W and Pb alloys: In-depth evaluation in elastic modulus, gamma-ray, and neutron attenuation for critical applications
ALMisned, Ghada; Susoy, Gulfem; Sen Baykal, Duygu; Alkarrani, Hessa; Güler, Ömer; Tekin, H.O.
This investigation assesses the gamma-ray and neutron attenuation properties of various alloys, including Pb90Cu10, A5, Manganin-R, Cu0.2Ag0.8, SA4, and W-based, to uncover efficient and cost-effective radiation shielding materials. Our study centers on alloys featuring elements such as lead, molybdenum, silver, and tungsten, selected for their unique protective qualities against radiation. Employing computational methods to evaluate critical parameters like mass attenuation coefficients, half-value layers, linear attenuation coefficients, and effective atomic numbers, transmission factor, we found the W-based alloy to exhibit exceptional shielding properties, primarily due to its tungsten content. Interestingly, this alloy also demonstrated the highest elastic modulus among the samples studied, indicating a potential synergy between an alloy's mechanical strength and its radiation shielding effectiveness. It can be concluded that alloys with higher elastic moduli not only offer better resistance to radiation-induced deformations, enhancing shielding, but also underscore the need for further research on alloys that balance performance, affordability, and environmental impact. The findings underscore the dual importance of composition and mechanical properties in advancing radiological safety and suggest continued investigation into the sustainability and practicality of effective shielding materials.
AtıfScopus28OpenAlex31İncele - MakaleAçık Erişim2024Scopus SJRQ1Development and in-depth experimental characterization of novel TiZrNbHfTaOx reinforced 316L stainless steel for advanced nuclear applications
Güler, Ömer; Albayrak, M. Gökhan; Başgöz, Öyküm; Kavaz, E.; Alkarrani, Hessa; ALMisned, Ghada; Tekin, H.O.
Oxide Dispersion Strengthened (ODS) materials are known for their exceptional performance in high-temperature and radiation environments. This study explores the radiation shielding properties of 316L Stainless Steel reinforced with TiZrNbHfTaOx High-Entropy Oxide (HEO). By integrating HEOs into the 316L stainless steel matrix, we aim to enhance its structural and radiation shielding properties. The HEO was synthesized using high-energy ball milling and oxidation processes, followed by thorough characterization using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). Our results indicate significant improvements in both gamma-ray and neutron shielding properties. The 316L SS samples reinforced with 20 % HEO exhibited the highest mass attenuation coefficients (MAC), lowest half-value layers (HVL), and highest effective atomic numbers (Zeff) across all tested photon energies. These enhancements are attributed to the high atomic number elements and unique synergistic effects of HEOs. Neutron shielding was evaluated through equivalent dose rate measurements, with the 20 % HEO sample demonstrating the highest absorbed dose rate percentage and superior neutron interaction cross-sections. Benchmarking against standard materials confirmed the superior performance of HEO-reinforced 316L SS, making it a promising candidate for advanced radiation shielding in nuclear reactors and other high-radiation environments. Our findings suggest that HEO reinforcement not only improves mechanical properties but also significantly enhances the radiation protection capabilities of 316L stainless steel.
AtıfScopus12OpenAlex13İncele - MakaleAçık Erişim2024Scopus SJRQ2Innovative Al6061-gadolinium oxide ods alloys: fabrication and comprehensive characterization of microstructural, physical, mechanical, and radiation shielding properties
ALMisned, Ghada; Yayla, Nihal; Albayrak, M. Gökhan; Güler, Ömer; Baykal, Duygu Sen; Tekin, H.O.
This study explores the development and comprehensive characterization of Al6061-Gd₂O₃ composites, designed to enhance radiation shielding and mechanical properties for critical applications in environments exposed to ionizing radiation. The purpose of this research is to assess the effectiveness of Gd2O3 as a reinforcing material for Al6061, with the aim of creating a dual-function composite that combines structural integrity with superior gamma-ray and neutron attenuation capabilities. Using X-ray diffraction (XRD) and scanning electron microscopy (SEM), we analyzed the microstructural effects of varying Gd2O3 content, observing homogeneous dispersion at low concentrations and clustering at higher levels. Mechanical properties demonstrated that increased Gd2O3 content reduces the elastic modulus, indicating a trade-off between stiffness and shielding efficiency. Radiation shielding parameters, including Transmission Factor (TF), mass attenuation coefficient (MAC), and Fast Neutron Removal Cross Section (FNRCS), were evaluated through Phy-X/PSD and PHITS Monte Carlo simulations. Results indicate that Gd2O3 reinforcement significantly improves gamma-ray and neutron shielding, particularly at higher concentrations, making the composite viable for non-structural applications prioritizing radiation protection. The findings from this study highlight the potential of Gd2O3-reinforced Al6061 composites to serve as effective shielding materials in environments where radiation exposure is a primary concern.
AtıfScopus4OpenAlex5İncele - MakaleAçık Erişim2024Scopus SJRQ2Photocatalytic Hydrogen Evolution of TiZrNbHfTaOx High-Entropy Oxide Synthesized by Mechano-Thermal Method
Güler, Ömer; Boyrazlı, Mustafa; Albayrak, Muhammet Gökhan; Güler, Seval Hale; Ishihara, Tatsumi; Edalati, Kaveh
One of the most promising solutions to slow down CO2 emissions is the use of photocatalysis to produce hydrogen as a clean fuel. However, the efficiency of the photocatalysts is not at the desired level, and they usually need precious metal co-catalysts for reactions. In this study, to achieve efficient photocatalytic hydrogen production, a high-entropy oxide was synthesized by a mechano-thermal method. The synthesized high-entropy oxide had a bandgap of 2.45 eV, which coincided with both UV and visible light regions. The material could successfully produce hydrogen from water under light, but the main difference to conventional photocatalysts was that the photocatalysis proceeded without a co-catalyst addition. Hydrogen production increased with increasing time, and at the end of the 3 h period, 134.76 µmol/m2 h of hydrogen was produced. These findings not only introduce a new method for producing high-entropy photocatalysts but also confirm the high potential of high-entropy photocatalysts for hydrogen production without the need for precious metal co-catalysts.
AtıfScopus33WoS30
İncele - MakaleAçık Erişim2024Scopus SJRQ1A comprehensive microstructural and transmission analysis on oxide dispersion-strengthened (ODS) alloys: Impact of erbium oxide (Er2O3) concentration on physical, structural, gamma-ray, and neutron attenuation properties
Günoglu, Kadir; Güler, Seval Hale; Güler, Ömer; ALmisned, Ghada; Ozkavak, Hatice Varol; Albayrak, M. Gokhan; Akkurt, Iskender; Issa, Bashar; Tekin, H.O.
This study explores the impact of integrating varying concentrations of Erbium Oxide (Er2O3) into Oxide Dispersion Strengthened (ODS) alloys, specifically focusing on gamma-ray and neutron attenuation properties. Utilizing a 316L stainless steel matrix, Er2O3 was methodically incorporated in concentrations ranging from 1 % to 21 % by weight. The structural and radiation attenuation properties of the resultant alloys were comprehensively analyzed using techniques such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and experimental gamma-ray transmission studies. The results demonstrate a significant enhancement in gamma-ray shielding with increased Er2O3 content. This enhancement is quantitatively evidenced by increased linear attenuation coefficient, elevated effective Electron Density (Neff), reduced Half-Value Layers (HVL), and higher effective atomic numbers (Zeff). These findings are crucial for nuclear applications where efficient gamma-ray shielding is paramount. Conversely, a decrease in the effective removal cross section (ΣR) for neutron attenuation was observed with higher Er2O3 concentrations. This suggests a potential compromise in neutron shielding efficiency, attributed to the dilution of neutron-absorbing base elements in the alloy. Additionally, the study reveals notable changes in the microstructural properties of the alloys, including alterations in particle size, distribution, and agglomeration, influenced by varying Er2O3 concentrations. In conclusion, this research provides valuable insights into the design of ODS alloys for nuclear radiation shielding, highlighting the balance between gamma-ray attenuation and neutron shielding properties. The study's findings contribute to the development of advanced materials for safer and more efficient nuclear technology applications.
AtıfScopus20OpenAlex25İncele - MakaleYalnız künye2024Scopus SJRQ2Exploring critical behavioral differences in physical, structural, and nuclear radiation attenuation properties of produced High Entropy Alloy (HEA) and Refractory-High Entropy Alloy (RHEA) samples
Güler, Seval Hale; Güler, Ömer; Kavaz, E.; Almisned, Ghada; Issa, Bashar; Tekin, H.O.
Refractory-High entropy alloys (RHEAs) are known for their exceptional mechanical and radiation-resistant properties, making them promising materials for use in nuclear reactors. Their high entropy composition, which consists of multiple elements in roughly equal proportions, can create a stable microstructure that withstands high levels of radiation damage. The objective of this work is to further our comprehension of the unique behavioral, physical, structural, and nuclear radiation attenuation characteristics shown by High-Entropy Alloys (HEA) and Refractory-High entropy alloy (RHEA) materials. Accordingly, two high entropy alloy (HEA) samples through two different compositions were produced. The first composition under consideration is the typical high-entropy alloy (HEA) defined as MnCrFeNiCoMo0.5. The second composition under consideration is a refractory high entropy alloy (RHEA) characterized by the following elemental composition: TiZrNbHfVTa0.1. SEM and EDX analyses were conducted in terms of determining their physical and structural attributes. Next, a133Ba radioisotope together with a HPGe detector were utilized for gamma-ray transmission experiments. Finally, a241Am/Be source and a gas proportional detector were used for neutron absorption experiments for HEA and RHEA samples. The alloy structures displayed a unique degree of uniformity. Throughout the RHEA phase, the incorporation of refractory elements did not provide any discernible adverse impacts on the physical stability. The counting spectrum provided a clear explanation of the gamma ray absorption features shown by the RHEA (R) sample, highlighting its exceptional absorption properties. Regarding the absorption properties of neutrons, it was observed that RHEA had a comparatively reduced amount of absorption. Therefore, it can be concluded that the basic structure of RHEA grants it superior gamma-ray attenuation qualities compared to HEA. It can be concluded that RHEA demonstrates superior applicability as a material in comparison to HEA, especially in situations involving the use of fuel rods, where maintaining of neutron quantity has paramount importance for achieving optimum neutron activation.
AtıfScopus26OpenAlex29İncele - MakaleYalnız künye2024Scopus SJRQ2Production of CoCrFeNi(Al/Ti) High-Entropy Alloys by Mechanical Alloying: Optimization of Milling Time and Comparison of Corrosion Susceptibilities
Say, Yakup; Dikici, Burak; Kaseem, Mosab; Özkul, İskender; Güler, Ömer
CoCrFeNi alloy is the most well-known four-component equiatomic alloy. In addition, it has a low-cost composition among HEAs. Four-component alloys are considered semi-HEAs. Therefore, a five-component HEA design was made by adding another metal to the main composition of CoCrFeNi. As the fifth metal, two metals such as Al and Ti, which are relatively low in cost and have the potential to improve properties, were chosen. For this purpose, in this study, the effect of Al and Ti on CoCrFeNi main alloy was investigated by producing three different samples as CoCrFeNi, CoCrFeNiAl, and CoCrFeNiTi. The alloys with three different compositions (used three different samples) were successfully produced by the mechanical alloying method. Although Al and Ti have the possibility of intermetallic with other metals in the alloy, such a formation was not observed during mechanical alloying, and it was observed that all metals were homogeneously distributed in the alloy. The microhardness results indicated that CoCrFeNiAl and CoCrFeNiTi samples had similar hardness values. While the hardness of the CoCrFeNi sample was 136 HV, the hardness of the CoCrFeNiAl sample was 262 HV. However, the hardness of the CoCrFeNiTi sample decreased significantly. The hardness of the CoCrFeNiTi sample was measured as 269 HV. It was observed that the addition of Ti and Al to the base alloy was increased a significant change in hardness. It has been observed that Ti supplementation has a more positive effect on improving corrosion properties. It is seen that the corrosion potentials shift toward more negative potentials with the addition of Al and Ti to the CoCrFeNi (−194 mV) alloy (−306 and −224 mV for CoCrFeNiAl and CoCrFeNiTi, respectively). When the surface morphologies of the alloys are compared after corrosion; the damage to the alloy surfaces increases due to the negative Ecorr value in CoCrFeNiAl and CoCrFeNiTi alloys compared to the master alloy. However, the high corrosion current density (12.69 µA/cm2) in the CoCrFeNiTi sample caused much more damage to this alloy. Graphical Abstract: (Figure presented.)
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