• MakaleAçık Erişim2024Scopus SJRQ1
    A 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.

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  • MakaleYalnız künye2024Scopus SJRQ2
    Exploring 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.

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  • MakaleYalnız künye2024Scopus SJRQ1
    First-ever fusion of high entropy alloy (HEA) with glass: Enhancing of critical properties of zinc-tellurite glass through TiZrNbHfTaOx incorporation

    Güler, Ömer; Kilic, G.; Kavaz, E.; Ilik, E.; Guler, Seval Hale; ALMisned, Ghada; Tekin, H.O.

    Many oxide additives have historically been used to enhance the radiation shielding properties of glasses, yet the potential of high-entropy oxides (HEOs), which have gained popularity in material science for their unique properties, has not been explored in this context. This study is the first to investigate the radiation shielding capabilities of Zinc-Tellurite glass infused with High Entropy Oxide (HEO), specifically utilizing the novel attributes of a synthesized TiZrNbHfTa. In this study, the nuclear shielding properties of newly fabricated Zinc-Tellurite glasses doped with TiZrNbHfTaOx with a composition (25ZnO·75TeO2)100-x. (TiZrNbHfTaOx)x (x = 0, 1, 2, 3, 4 mol%) were studied. Through the synthesis of a TiZrNbHfTa HEA and its integration into glass structure, we have developed a series of novel materials with enhanced protective properties against both gamma-ray and neutron radiation. Experimental results demonstrate that the HEO-infused glass, particularly the HEC1-4 composition, significantly surpasses traditional shielding materials in neutron attenuation, evidenced by its superior effective neutron removal cross-section. Additionally, the HEC1-4 glass demonstrates improved gamma-ray shielding capabilities, with increased mass attenuation coefficients and decreased half-value layers, indicating a higher capacity for photon interaction and absorption. It can be concluded that the incorporation of High Entropy Alloys into glass matrices not only opens a new frontier in radiation shielding materials but also provides a versatile and effective solution with considerable potential for enhancing safety measures in radiation-prone environments.

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  • MakaleYalnız künye2024Scopus SJRQ2
    A first-time fusion of TiNbWMoZrOx high entropy oxide (HEO) with zinc-tellurite glass: Toward superior physical properties

    Kilic, G.; Güler, Ömer; Kavaz, E.; Ilik, E.; Guler, Seval Hale; ALMisned, Ghada; Tekin, H.O.

    While numerous oxide additives have traditionally been employed to enhance the radiation shielding capabilities of glasses, the unique attributes of high-entropy oxides (HEOs), a group of materials acclaimed in contemporary material science for their distinctive properties have remained unexamined in this specific area. This novel study explores the enhancement of radiation shielding properties in zinc-tellurite glasses through the integration of TiNbWMoZrOx High Entropy Oxides (HEO). Utilizing advanced synthesis techniques, including mechanical alloying and oxidation, the research successfully incorporates HEOs into glass matrices, aiming to improve gamma-ray and neutron attenuation. Characterization through X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) confirms the uniform distribution and structural integrity of the HEOs within the glasses. The synthesis of glass samples with a base structure suitable for the molar composition of 25ZnO.75TeO2 (mol%) and glass samples doped with TiNbWMoZrOx (HEO) was carried out using the traditional high-temperature melting and annealing method. The outcomes demonstrate a concentration-dependent increase in shielding efficacy, particularly highlighting the superior performance of glasses doped with 4 mol% of TiNbWMoZrOx (HEC2–4), which exhibit significantly enhanced mass attenuation coefficients, lower half-value layers, and higher effective atomic numbers. This indicates the effective role of HEOs in boosting radiation protection capabilities. Comparative analysis with traditional shielding materials showcases the HEC2–4 glasses' competitive advantage, underlining their potential as a versatile shielding solution. It can be concluded that incorporating TiNbWMoZrOx high entropy oxides into zinc-tellurite glasses significantly augments their radiation shielding properties, offering a novel approach for enhancing protection against gamma-ray and neutron in various applications.

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  • MakaleYalnız künye2023Scopus SJRQ2
    Graphene nanoplatelet-reinforced high entropy alloys (HEAs) through B4C incorporation: structural, physical, mechanical, and nuclear shielding properties

    Gul, Ali Oktay; Kavaz, Esra; Basgoz, Oykum; Guler, Omer; ALMisned, Ghada; Bahceci, Ersin; Guler, Seval Hale; Tekin, H.O.

    This study aims to explicate the diverse roles of high entropy alloys within nuclear environments. The study extensively investigates the impact of B4C on the structural, physical, mechanical, and nuclear shielding properties of synthesized high-entropy alloys (HEAs) comprising FeNiCoCrW, GNP, and B4C. The aim is to explore the monotonic effects of B4C on the behavioural changes of the HEAs. The present study initially investigates the internal morphology and structural characteristics of the produced composites through the utilization of X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. The determination of coefficient of friction values is obtained via wear testing, wherein the values are measured as a function of the sliding distance. The shielding properties of nuclear radiation are determined through the experimental setups for gamma-ray and neutron radiation. The sample encoded as G2, which incorporates both B4C and GNPs as reinforcing agents, exhibits the most noteworthy mechanical properties among the samples that were examined. The findings of our study indicate that augmenting the concentration of B4C has a significant impact on the efficacy of nuclear radiation shielding. The present study infers that the B4C produced within the framework of GNPs plays a significant role in enhancing the overall characteristics of HEAs. This is particularly noteworthy in the context of nuclear applications, where HEAs are being examined as a prospective constituent of forthcoming nuclear reactors. Moreover, B4C serves as a versatile instrument in scenarios, where there is a need to enhance mechanical and nuclear shielding properties across a spectrum of radiation energies.

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  • MakaleAçık Erişim2023Scopus SJRQ1
    FeCoNiMnCr high-entropy alloys (HEAs): Synthesis, structural, magnetic and nuclear radiation absorption properties

    Şimşek, Telem; Kavaz, Esra; Güler, Ömer; Şimşek, Tuncay; Avar, Barış; Aslan, Naim; Almisned, Ghada; Zakaly, Hesham M.H.; Tekin, H.O.

    We report the synthesis and structural, magnetic and Radiation shielding properties of High Entropy Alloy (HEA) produced through mechanical alloying method. Using an X-Ray Diffractometer (PanalyticalEmpryan) with CuK radiation at 45 kV and 40 mA, the phase identification starting elements and as-milled powders are identified. Scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX), morphological and microstructural investigations were conducted (FEI Quanta FEG 450). EDX and elemental mapping analyses are conducted to assess the purity and elemental distributions of the synthesized alloys. Using the Quantum Design Physical Characteristics Measurement System (PPMS) with vibrating sample magnetometer (VSM) and a magnetic field of 30 kOe at room temperature, magnetic properties are examined. Using 137Cs radioisotope and mathematical methods, gamma-ray and neutron shielding properties of HEA are investigated in a conventional transmission setup using experimental and theoretical approaches. In the presence of a 3 T applied field, the sample exhibits a low magnetization of 5.30 emu/g at 300 K. Moreover, Ms is raised to 22 emu/g at 10 K owing to decreased thermal effects. The temperature dependence of the magnetization is recorded in the presence of a 1 T applied field. HEA exhibits superior neutron attenuation properties than conventional absorption materials such as B4C, graphite, and water. Our results showed that the synthesized HEA has superiority over other alloys and conventional neutron absorption materials. It can be concluded that the proposed novel HEA might be investigated further in terms of broadening its characterization and clarifying its other crucial properties to extend the scope of the current investigation.

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  • MakaleYalnız künye2023Scopus SJRQ1
    Oxides dispersion-strengthened (ODS) FeCoNiCuZn high entropy alloys through different rare earth elements: Synthesis, structural, physical, and experimental radiation transmission properties

    Güler, Ömer; Kavaz, E.; Güler, Seval Hale; Almisned, Ghada; Özkul, İskender; Basgoz, Oykum; Tekin, H.O.

    The oxide dispersoids within ODS alloys can act as sinks for radiation-induced defects, such as vacancies and dislocation loops, effectively reducing their mobility and preventing their accumulation. This property is crucial for HEAs employed in radiation-intensive environments, such as nuclear reactors. The objective of this research is to examine the impact of rare earth elements (REE) such as Y2O3, Er2O3, Pr2O3, and Sm2O3, on Oxides Dispersion-Strengthened (ODS) FeCoNiCuZn High Entropy Alloys (HEAs). The mechanical alloying technique is employed to produce a high entropy alloy consisting of Fe, Co, Ni, Cu, and Zn in their raw form. Subsequently, the raw alloy powder is enriched with separate amounts of Y2O3, Er2O3, Pr2O3, and Sm2O3. The microstructural analysis of the samples obtained from the mechanical alloying process was performed utilizing the X-ray diffraction (XRD) technique. In addition, scanning electron microscopy (SEM) was employed to analyze the ODS-HEA samples encoded S1, S2, S3, S4, and S5. To investigate the transmission properties of gamma-ray and neutron radiation, experimental studies are carried out using two types of detectors: Ultra High Purity Germanium (HPGe) detector and Canberra NP-100B BF3 gas proportional detector, respectively. The X-ray diffraction (XRD) spectra of samples did not display any observable peaks that could be attributed to the presence of dispersed rare earth element (REE) oxides. The uniform distribution of the metallic constituents that make up the High Entropy Alloy (HEA) is observed in the samples. Additionally, it can be observed that the implementation of the ODS-HEA technique, incorporating a 3% (wt.) Er2O3 additive, results in the most advantageous results with respect to the characteristics of gamma ray absorption. The S3 sample demonstrated the greatest degree of neutron absorption, as demonstrated by a recorded value of 0.857 μSv/h, where the S1 sample demonstrated the minimum level of absorption, as evidenced by a recorded value of 0.452 μSv/h. Based on the observed effects on neutron and gamma-ray attenuation behaviors in ODS-HEAs, it can be concluded that Er2O3 exhibits characteristics of a monotonic oxide. This feature is particularly advantageous for applications that necessitate a dual enhancement in these behaviors. It can also be concluded that the S1 sample may be deemed appropriate for situations where the utmost consistency of chain reactions in nuclear reactor fuel rods is desired, due to its possession of the lowest neutron absorption properties.

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  • MakaleAçık Erişim2022Scopus SJRQ1
    Newly synthesized NiCoFeCrW High-Entropy Alloys (HEAs): Multiple impacts of B4C additive on structural, mechanical, and nuclear shielding properties

    Gul, Ali Oktay; Kavaz, Esra; Basgoz, Oykum; Guler, Omer; ALMisned, Ghada; Bahceci, Ersin; Albayrak, M. Gokhan; Tekin, H.O.

    High-Entropy Alloys (HEAs) are regarded as potential structural materials for fusion and next-generation fission reactors, which will be required to fulfil growing nuclear energy demands. In this study, a HEA-composite was synthesized by adding B4C to an HEA containing Ni. The microstructure of the obtained HEA-composite was examined and the changes in its mechanical properties were revealed. Additionally, the nuclear radiation shielding properties of the Ni-containing HEA, and the HEA-composite are investigated using experimental and theoretical methods. Our initial findings showed that with the addition of 2.5% B4C to the alloy, the hardness increased more than two times. The addition of B4C to the HEA matrix resulted in a more than 90% and a nearly twofold increase in compressive strength. The shielding qualities of gamma-ray and neutron radiation were investigated using experimental and theoretical approaches. Our findings demonstrated that increasing the B4C reinforcement considerably enhanced the composite material's neutron attenuation capabilities. On the other hand, no significant change in the gamma-ray shielding characteristics of HEA and HEA-composite samples was observed. The gamma-ray shielding characteristics of HEA and HEA-composite samples were compared to those of other alloy shields and commercial products. Our findings indicate that both HEA and HEA-composite samples exhibit superior gamma-ray shielding characteristics when compared to the control samples. It can be concluded that increasing B4C reinforcement may be a multifunctional tool in terms of improving the mechanical properties as well as neutron attenuation properties for advanced applications in nuclear radiation facilities and next-generation fission reactors. Additionally, due to their promising material features and higher gamma-ray shielding capabilities compared to other kinds of alloys and commercial shields, HEAs may be beneficial materials.

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  • MakaleAçık Erişim2022Scopus SJRQ2
    Synergistic effect of boron nitride and graphene nanosheets on behavioural attitudes of polyester matrix: Synthesis, experimental and Monte Carlo simulation studies

    Başgöz, Öyküm; Güler, Seval Hale; Güler, Ömer; Canbay, Canan A.; Zakaly, Hesham M.H.; Issa, Shams A.M.; ALMisned, Ghada; Tekin, H.O.

    We report the synergistic effects of boron nitride and graphene nanosheets on physical, structural, and nuclear radiation attenuation properties of polyester matrix-incorporated nanocomposites. Some critical material properties are thoroughly evaluated for several types of synthesized samples. Polyester is employed to strengthen graphene and boron nitride nanolayers, and their characteristics are investigated in detail. Additionally, we report the gamma-ray and fast neutron attenuation characteristics of synthesized nanocomposites to get a better understanding of the reinforcing effect as a function of material type and weight percentage. Thermal analysis findings indicate that adding graphene lowers the decomposition temperature but co-adding graphene and BNNS enhances thermal decomposition in comparison to graphene itself. Tensile tests showed that the inclusion of both GRP and GRP/BNNS strengthens the material. Among the polyester composite samples analyzed, the G3 sample with the most GNP reinforcement had the lowest HVL values throughout the broadest range of energy levels investigated. The recent findings may be beneficial to the scientific community in terms of incorporating these reinforcing types and ratios into polyester materials for a variety of applications, including industrial and research purposes.

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  • DüzeltmeAçık Erişim2022Scopus SJRQ2
    Correction to: Boron nitride nanosheet-reinforced WNiCoFeCr high-entropy alloys: the role of B4C on the structural, physical, mechanical, and radiological shielding properties (Applied Physics A, (2022), 128, 8, (694), 10.1007/s00339-022-05813-5)

    Kavaz, Esra; Gul, Ali Oktay; Basgoz, Oykum; Guler, Omer; ALMisned, Ghada; Bahceci, Ersin; Guler, Seval Hale; Tekin, H.O.

    In this article the affiliation 7 was incorrectly assigned to all authors but H.O. Tekin.

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  • MakaleAçık Erişim2022Scopus SJRQ1
    Synthesis and structural, electrical, optical, and gamma-ray attenuation properties of ZnO-multi-walled carbon nanotubes (MWCNT) composite separately incorporated with CdO, TiO2, and Fe2O3

    Basgoz, Oykum; Guler, Omer; Evin, Ertan; Yavuz, Cagdas; ALMisned, Ghada; Issa, Shams A.M.; Zakaly, Hesham M.H.; Tekin, H.O.

    In this study, Fe2O3, TiO2, and CdO semiconductor metal oxides were separately incorporated into the ZnO-MWCNT composite at different weight percentages. Accordingly, several experimental analyses on electrical, optical, and radiation shielding characteristics of coupled semiconductor metal oxides nanocomposites were performed to determine their monotonic impact on the investigated material properties. Moreover, gamma-ray shielding properties of these novel materials were determined using MCNPX general-purpose Monte Carlo code. At 5% oxide addition, the maximum electrical conductivity was found in all groups for all temperatures. Moreover, 5% oxide reinforcement resulted in the maximum reflection characteristics in all groups. Among the CdO doped materials, the CZnOCd5 sample exhibits the highest electrical conductivity behaviour at room and high temperatures. The Eg value calculated for the CZnOCd5 sample was 3.284 eV. The CZnOCd2.5 and CZnOCd5 samples had the greatest Eg values when compared to the pure sample and the samples from other groups. The CZnOCd5 sample has the highest reflectance value in the CZnOCd group's reflectance graph. On the other hand, the maximum gamma-ray attenuation properties were reported for CZnOCd5 sample. Among the analysed samples, the CZnOCd5 sample's characteristics provide a preliminary motivation for a more comprehensive analysis of this material and assessment of potential radiation protection applications.

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  • MakaleYalnız künye2022Scopus SJRQ2
    Boron nitride nanosheet-reinforced WNiCoFeCr high-entropy alloys: the role of B4C on the structural, physical, mechanical, and radiological shielding properties

    Kavaz, Esra; Gul, Ali Oktay; Basgoz, Oykum; Guler, Omer; ALMisned, Ghada; Bahceci, Ersin; Guler, Seval Hale; Tekin, H.O.

    The synthesis and extensive characterization of newly developed boron nitride nanosheet (BNNSs)-reinforced WNiCoFeCr high-entropy alloys (HEAs) are presented. The influence of B4C on the structural, physical, mechanical, and nuclear shielding characteristics of synthesized HEAs has been widely examined in terms of its monotonic effects on the behavior changes. The internal morphology and structural characteristics of the fabricated composites are first investigated using X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. Wear testing is used to determine the coefficient of friction as a function of sliding distance. Experimental gamma ray and neutron setups are created to determine their shielding characteristics against nuclear radiation. Finally, the shielding characteristics of nuclear radiation for gamma ray and fast neutrons are compared extensively to those of many existing and new-generation shielding materials. Among the examined samples, the S2 sample with B4C and BNNSs reinforcement had the greatest mechanical characteristics. Our findings imply that increasing B4C directly contributes to the shielding qualities of nuclear radiation. The B4C created in the structure of BNNSs contributes to the overall properties of HEAs, which are crucial for nuclear applications, since HEAs are being examined as a component of future nuclear reactors. Additionally, B4C is a very versatile material that may be used in circumstances where mechanical and nuclear shielding properties need to be enhanced for a variety of radiation energies.

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