Albayrak, Muhammet Gökhan; Güler, Ömer; Güler, Seval Hale; Evin, Ertan; ALMisned, Ghada; Sen Baykal, Duygu; Alkarrani, Hessa; Susoy, Gulfem; Kilic, Gokhan; Tekin, Hüseyin Ozan

This study explores the physical, structural, and radiation shielding enhancements in Inconel 718 superalloys reinforced with 1 wt% Y2O3 and varying Pr2O3 contents from 0 to 10 wt%, respectively. X-ray diffraction analysis confirmed preservation of the face-centered cubic structure, with increasing Pr2O3 inducing peak broadening and partial amorphization. The scanning electron microscopy/energy-dispersive X-ray spectroscopy results verified the homogeneous dispersion of oxides without agglomeration. Gamma-ray shielding parameters, including the mass attenuation coefficient (MAC), half-value layer, and effective atomic number, significantly improved with higher Pr2O3 content, particularly at low to mid photon energies. The 718Y-10PO sample exhibited the lowest transmission factors and the highest MAC values across all the tested energies. Buildup factors decreased in the Pr-rich samples, confirming reduced photon scattering. Notably, the fast neutron removal cross section for 718Y-10PO as 0.15521 cm−1 exceeded the benchmark materials like graphite and B4C. These findings establish the 718Y-10PO alloy as a promising candidate for advanced nuclear shielding applications, combining structural integrity with promising gamma and neutron attenuation capabilities.

İncele

Özkul, İskender; Kalay, Ece; Güler, Seval Hale; Karaduman, Oktay; Şimşek, Telem; Bülbül, Zeynel Abidin; Aksu Canbay, Canan; Sen Baykal, Duygu; ALMisned, Ghada; Tekin, H.O.

Rare-earth substitution provides a route for tailoring the structural, magnetic, and gamma-ray attenuation behaviour of Ho-based Co-Mn double perovskites; however, the combined effects of rare-earth ionic size, magnetic character, and substitution level remain insufficiently understood. In this study, Ho1.5La0.5CoMnO6, Ho1.2Er0.8CoMnO6, Ho1.3Sm0.7CoMnO6, and Ho2CoMnO6 were synthesized through a two-step route involving mechanical alloying to obtain precursor powders, followed by annealing at 1000 °C in air to promote oxidation and double-perovskite phase formation. Their structural, thermal, surface-chemical, magnetic, and gamma-ray attenuation properties were examined by X-ray diffraction, thermal analysis, X-ray photoelectron spectroscopy, SEM-EDS, vibrating-sample magnetometry, and theoretical shielding calculations based on half-value layer (HVL) and transmission factor (TF) parameters. The XRD patterns were consistent with predominantly monoclinic P21/n type double-perovskite structures, while weak additional reflections suggested possible minor secondary phases. SEM-EDS showed homogeneous elemental distributions, and XPS analysis indicated Co2+ dominated and mixed Mn-valence characteristics in the spectra where reliable component analysis was possible. All compositions exhibited a low-temperature ferromagnetic-like field response but did not reach magnetic saturation at 3 T. Ho2CoMnO6 and Ho1.3Sm0.7CoMnO6 showed the highest field-dependent magnetization values at 10 K, whereas Ho1.2Er0.8CoMnO6 displayed the lowest response. The theoretical gamma-ray attenuation calculations showed clear composition-dependent differences. At 0.662 MeV, the HVL values were 1.0650, 0.9972, 1.0438, and 0.9967 cm for Ho1.5La0.5CoMnO6, Ho1.2Er0.8CoMnO6, Ho1.3Sm0.7CoMnO6, and Ho2CoMnO6, respectively. At the same photon energy and a thickness of 1.0 cm, the corresponding TF values were 0.0896, 0.0858, 0.0882, and 0.0860. Thus, Ho1.2Er0.8CoMnO6 and Ho2CoMnO6 exhibited the lowest HVL and TF values among the investigated compositions. The shielding calculations identified Ho1.2Er0.8CoMnO6 and Ho2CoMnO6 as the most effective attenuators, with lower HVL and TF values across the investigated energy range. These results show that rare-earth substitution enables compositional tuning of magnetic and theoretical gamma-ray attenuation behaviour, with the observed trends reflecting the combined influence of rare-earth ionic size, magnetic character, substitution level, and valence-state complexity.

İncele

Yayla, Nihal; Albayrak, M. Gökhan; Güler, Ömer; Sen Baykal, Duygu; Alkarrani, Hessa; ALMisned, Ghada; Tekin, H.O.

Type 316L stainless steel (316L-SS) is widely recognized for its exceptional corrosion resistance, making it a preferred material in various industries. However, conventional stainless steel materials are inadequate for radiation shielding applications. While oxide dispersion-strengthened alloy composites with a 316L-SS matrix have been extensively studied in the literature for their mechanical creep properties, their radiation shielding capabilities remain insufficiently explored. This study investigates the potential of samarium oxide (Sm2O3) doped to improve the structural, physical, mechanical, and radiation shielding properties of 316L-SS composites. Samples containing 1%, 5%, 10%, and 20% Sm2O3 by weight were synthesized and extensively characterized using X-ray diffraction and scanning electron microscopy. These analyses revealed enhanced homogeneity and refined grain structure with increasing Sm2O3 content. Gamma-ray and neutron shielding properties demonstrated significant improvements, particularly in composites with 20% Sm2O3 reinforcement, as evidenced by lower half-value layer and mean free path values, along with an increased fast neutron removal cross section. However, a trade-off was observed between radiation shielding performance and mechanical properties: As the Sm2O3 content increased, the elastic modulus decreased, indicating reduced stiffness due to the incorporation of Sm2O3. This trade-off suggests that while Sm2O3 reinforcement effectively enhances radiation shielding, it may not be ideal for structural applications requiring high mechanical strength. Nevertheless, these findings highlight the potential of Sm2O3-doped 316L-SS composites for nonstructural radiation protection systems, particularly in applications where improved shielding performance is prioritized over mechanical stiffness.

AtıfScopus5·OpenAlex7

İncele

Guler, Seval Hale; Yayla, Nihal; Guler, Omer; ALMisned, Ghada; Sen Baykal, Duygu; Kilic, Gokhan; Tekin, Huseyin Ozan

In this study, 6061-aluminum metal matrix composites doped with varying concentrations of ytterbium(III) oxide were synthesized using high-energy mechanical alloying to evaluate their structural, physical, and radiation shielding properties. X-ray diffraction confirmed the retention of the aluminum crystal structure with no secondary phase formation, while scanning electron microscopy and energy-dispersive X-ray spectroscopy revealed homogenous dispersion of Yb2O3 particles within the matrix. With increasing Yb2O3 content, particle densification and structural integrity were significantly enhanced. Gamma-ray and neutron shielding performance was assessed through theoretical modeling and Monte Carlo simulations. At low photon energy, the 20 wt% Yb2O3 composites showed a remarkable increase in linear attenuation coefficients compared to the undoped 6061-aluminum matrix. Neutron removal efficiency also increased by 32% at the highest Yb2O3 content. It can be concluded that Yb2O3 incorporation significantly improves both the photon and neutron shielding performance of the 6061-aluminum metal matrix.

İncele

Simsek, Tuncay; Simsek, Telem; Chattopadhyay, Arun K.; Avar, Barış; Yakin, Alican; Guler, Seval Hale; Almisned, Ghada; Sen Baykal, Duygu; Tekin, H.O.

In this study, mechanically alloyed Fe70Nb10V10B10, Co70Nb10V10B10, Ni70Nb10V10B10, and (FeCoNi) 70Nb10V10B10 high-entropy alloys were successfully synthesized, and their structural, magnetic, and radiation shielding properties were systematically investigated. Structural analysis revealed that Fe favored bcc phase formation, while Co and Ni stabilized fcc structures; the equiatomic alloy resulted in a single-phase fcc solid solution with the smallest crystallite size (2.1 nm). All samples exhibited soft ferromagnetic behavior, with the Fe-based alloy achieving the highest saturation magnetization (120 emu/g), and the (FeCoNi) 70Nb10V10B10 alloy displaying the lowest coercivity. Among all compositions, Co70Nb10V10B10 demonstrated the best gamma and neutron shielding performance, showing the highest linear attenuation coefficient and fast neutron removal cross-section. The equiatomic alloy also exhibited well-balanced and stable shielding behavior. These findings position Co70Nb10V10B10 as a promising candidate for multifunctional applications requiring both efficient radiation protection and favorable magnetic properties.

AtıfScopus1

İncele

Güler, Ömer; Güler, Seval Hale; Özkul, İskender; ALMisned, Ghada; Sen Baykal, Duygu; Tekin, H.O.

Spinel high-entropy oxides (HEOs) can stabilize multiple transition-metal cations within a single lattice, yet their radiation-interaction behavior is scarcely explored. Here, a (FeNiCoCrMn)3O4 spinel HEO was produced via an alloy-to-oxide route: 40 h mechanical alloying of equiatomic FeNiCoCrMn powders followed by mechano-oxidation (1000 °C/3 h) and high-energy grinding. HEA-derived thermodynamic metrics were used to rationalize the stability of the equiatomic metallic precursor prior to mechano-oxidation, rather than to directly predict the formation of the final oxide phase. XRD evidenced progressive amorphization of the HEA and its conversion to a crystalline spinel oxide, while SEM–EDS confirmed homogeneous elemental distribution. XPS indicated a defect-rich, multivalent surface (Co2+/Co3+, Cr3+/Cr6+, Fe3+, mixed Mn states, Ni2+) with lattice oxygen and vacancy-related components. Moreover, the spinel oxide showed higher linear attenuation coefficients than 316L stainless steel, Inconel-718, and several lightweight Al-based entropy alloys, yielding lower HVL values, especially at low energies. Zeff exhibited the expected energy dependence and exceeded Al-dominant alloys across the spectrum. EBF/EABF at 1 and 40 mfp displayed Compton-region peaks and strong depth effects, consistent with attenuation behavior. It can be concluded that a (FeNiCoCrMn)3O4 spinel high-entropy oxide, produced via an alloy-to-oxide transformation route, exhibits structurally stable and compositionally homogeneous characteristics together with favorable gamma-ray attenuation behavior.

İncele

Güler, Ömer; Özkul, İskender; Almisned, Ghada; Sen Baykal, Duygu; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.; Tekin, H.O.

This study explores the development and characterization of 18 novel ZrWNb[(X)(Y)] (where XY are Hf, Ta, Mo, V, Ti) refractory high entropy alloys (RHEAs) designed to enhance mechanical robustness, thermodynamic stability, and radiation shielding effectiveness. Through a rigorous analysis, we evaluated the elastic modulus, entropy, and enthalpy of mixing, atomic size difference, valence electron concentration, and the omega parameter to understand the alloys’ phase behavior and structural integrity. Our findings revealed a broad range of elastic modulus values, indicating diverse mechanical adaptability suitable for high-stress applications. The thermodynamic assessment highlighted several RHEAs with favorable phase stability, particularly ZrWNbTaHf and ZrWNbTiTaHf, which are poised for high-performance usage due to their balanced mixing entropy and enthalpy. This study also benchmarks the RHEAs against conventional alloys, with sample R1 exhibiting the lowest fast neutron effective removal cross section, underscoring its superior neutron shielding capabilities. Additionally, R1 demonstrated exceptional photon attenuation, as evidenced by its competitive half-value layer performance across an extensive energy spectrum. Collectively, these results position R1 as a standout candidate, offering a significant advancement in materials science for applications demanding stringent radiation shielding, such as in nuclear reactor environments and space exploration.

AtıfScopus4·OpenAlex5

İncele

Yayla, Nihal; Albayrak, M. Gökhan; Güler, Ömer; Almisned, Ghada; Sen Baykal, Duygu; Alkarrani, Hessa; Kilic, Gokhan; Tekin, Huseyin Ozan

This study provides one of the first comprehensive evaluations of 316L stainless steel composites reinforced with 10 wt.% B4C and varying concentrations of Ho2O3, proposing a new compositional design for simultaneous structural enhancement and dual gamma-neutron shielding optimization. XRD analysis confirmed the predominance of the austenitic phase with minor martensitic peaks at higher Ho2O3levels. SEM and EDX results revealed uniform dispersion and improved densification with increasing oxide content. The 316L-B4C-20%Ho2O3composite exhibited the highest mass attenuation coefficient (0.8953 cm2/g) and linear attenuation coefficient (6.73 cm−1) at 0.1 MeV, demonstrating superior gamma-ray shielding capability. The effective electron density increased from 2.86 × 1023to 5.82 × 1023electrons/cm³, while the energy absorption buildup factor (EABF) showed a consistent decrease with higher oxide concentrations. Although a slight reduction in fast neutron removal cross-section was observed, the composite maintained satisfactory neutron attenuation performance. Overall, the findings indicate that the 316L-B4C-20%Ho2O3system offers a promising balance between structural stability and dual radiation protection, making it a strong candidate for next-generation nuclear shielding materials.

AtıfScopus1

İncele

Yayla, Nihal; Albayrak, M Gökhan; Güler, Ömer; Sen Baykal, Duygu; Alkarrani, Hessa; ALMisned, Ghada; Issa, Bashar; Tekin, H.O.

This study investigates the multi-dimensional effects of increasing Gd2O3 reinforcement on the structural, mechanical, and gamma-ray shielding properties of AISI 316L stainless steel composites. Samples with varying Gd2O3 content (1%, 5%, 10%, and 20% by weight) were synthesized and characterized through x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) to assess the microstructural changes and homogeneity of Gd2O3 dispersion after mechanical milling. The addition of Gd2O3 significantly enhanced the gamma-ray shielding properties, with the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), and half-value layer (HVL) improving as the Gd2O3 content increased, particularly in low to moderate photon energy ranges. Simultaneously, the elastic modulus exhibited an inverse relationship, decreasing with higher Gd2O3 content due to the lower stiffness of gadolinium compared to iron. Transmission factor (TF) values also decreased, indicating enhanced photon attenuation with higher Gd2O3 content across various thicknesses. The experimental characterization confirmed improved Gd2O3 dispersion and material uniformity after mechanical milling, contributing to the composites’ superior radiation shielding performance. It can be concluded that Gd2O3-reinforced AISI 316L stainless steel composites offer a promising balance between enhanced radiation shielding properties and reduced mechanical stiffness, making them ideal candidates for applications requiring efficient and adaptable radiation protection especially for portable and non-structural shielding applications.

AtıfScopus3·OpenAlex3

İncele

ALMisned, Ghada; Yayla, Nihal; Albayrak, M. Gökhan; Güler, Ömer; Sen Baykal, Duygu; Alkarrani, Hessa; Susoy, Gulfem; Tekin, H.O.

Oxide dispersion-strengthened alloys have emerged as a highly effective solution to address the physical, structural, and shielding challenges faced by traditional alloys in nuclear environments. This study presents a comprehensive evaluation of the microstructural, mechanical, and radiation shielding properties of Yb2O3 oxide dispersion-strengthened 316L stainless steel composites at varying Yb2O3 concentrations such as 1%, 5%, 10%, and 20% by weight. XRD analysis revealed lattice distortions, with crystallite sizes decreasing from 11.2267 nm to 9.3351 nm. SEM/EDX analyses confirmed homogeneous Yb2O3 dispersion at lower concentrations, with agglomeration at 20% Yb2O3. The mass attenuation coefficient increased from 56.103 cm2/g to 65.919 cm2/g at 0.015 MeV, marking a 17.5% enhancement. HVL decreased by 40.68% at 0.2 MeV for the 20% Yb2O3 sample. Additionally, the 20% Yb2O3 composite showed nearly 33% lower transmission factor at 3.0 cm thickness and 0.662 MeV. It can be concluded that Yb2O3 reinforcement significantly enhances the microstructural, and gamma-ray attenuation properties of 316L-SS composites, positioning them as promising materials for advanced nuclear shielding and structural applications.

AtıfScopus5·OpenAlex5

İncele

ALMisned, Ghada; Guler, Omer; Ozkul, Iskender; Sen Baykal, Duygu; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.; Tekin, H.O.

To qualify for nuclear applications, materials must meet specific criteria, including mechanical properties, high-temperature behavior, corrosion resistance, and high-temperature oxidation resistance. High Entropy Alloys (HEAs) are particularly suitable for these applications due to their unique properties. Consequently, we conducted a theoretical and simulation-based approaches to assess some critical properties including radiation shielding properties of some quinary FeNiCoCr HEAs. In this study, we focused on quinary FeNiCoCr HEAs, whose corrosion properties have been previously examined in the literature. We investigated the thermodynamic and radiation shielding properties of HEAs with sixteen different compositions. Our methodology included evaluating thermodynamic parameters such as Mixing Entropy (∆Smix) and Mixing Enthalpy (∆Hmix), as well as structural characteristics like Valence Electron Concentration (VEC) and Atomic Size Difference (δ). This allowed us to systematically deduce the phase behavior and stability of various HEAs. Through computational modeling, we assessed the radiation shielding capabilities of these alloys, particularly their effectiveness in attenuating gamma ray and fast neutrons. The results identified FeNiCoCrW as the alloy with the lowest fast neutron removal cross-section values, highlighting its potential for nuclear applications. Its high melting point and the synergistic interplay between its elemental composition and thermodynamic properties suggest broad applicability in extreme environments. Thus, FeNiCoCrW emerges as a promising HEA with multifunctional capabilities, warranting further exploration and potential integration into advanced engineering solutions.

AtıfScopus8·OpenAlex10

İncele

ALMisned, Ghada; Guler, Omer; Sen Baykal, Duygu; Kilic, G.; Tekin, H.O.

Titanium alloys play a vital role in optimizing the effectiveness and security of nuclear reactors, strengthening structural durability, and facilitating the effective handling of nuclear waste. The aim of this study is to investigate the gamma-ray, neutron, and transmission properties of four common titanium alloys through the examination of the deposited energy amount in the liquid sodium coolant material, in relation to the mechanical properties of these alloys. MCNP (version 6.3) is utilized for designing the titanium pipes. Next, the pipes were re-designed considering the elemental mass fractions and densities of the investigated titanium alloys. Grade 26 sample is reported with the highest values of mass attenuation coefficients and the lowest HVL values among those investigated alloys. Grade 26 is reported to have the lowest TF value, whereas Grade 12 demonstrated the highest TF value. The highest Effective Removal Cross Section (ΣR, 1/cm) value against fast neutrons is reported for Grade 26. The utilization of Grade 26 sample as pipe material resulted in the lowest deposited energy amount (MeV/g) and subsequent lowest contamination in the coolant material. Out of the alloys that were chosen for analysis, it has been determined that Grade 26 exhibits the highest level of strength. It can be concluded that the Grade 26 alloy exhibits desirable characteristics for applications in nuclear technologies that require superior gamma-ray and neutron absorption properties, as well as exceptional mechanical properties. Nevertheless, it is essential to emphasize the importance for ongoing studies to enhance the existing material properties of Grade 26, with the aim of achieving improved safety and efficacy in nuclear applications.

AtıfScopus11·OpenAlex11

İncele

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.

AtıfScopus28·OpenAlex31

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