Sürdürülebilir Kalkınma Amaçları
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- MakaleAçık Erişim2026Scopus SJRQ1Comparative effects of La2O3 and Sm2O3 on structural and radiation shielding properties of WO3 enriched borate glassy-ceramics
Taşgın, Yahya; Yılmaz, Demet; Kanca, M. Sait; Yayla, Nihal; Kök, Mediha; Güler, Ömer
This research comprehensively investigates the impact of incorporating rare earth oxides ‑samarium oxide (Sm2O3) and lanthanum oxide (La2O3)- into a borate glassy-ceramic system enriched with tungsten oxide (WO3), with a focus on both structural characteristics and radiation shielding performance. SEM-EDS, elemental mapping, and XRD analyses conducted on the synthesized glassy-ceramic samples revealed that the incorporated rare earth oxides, Sm2O3 and La2O3, were uniformly distributed throughout the glassy-ceramic matrix. The results also confirmed that the glassy-ceramic retained its inherently amorphous structure. Moreover, the nominal doping levels of the rare earth elements were found to be in agreement with both the qualitative and quantitative results obtained from EDS measurements. Also, the gamma ray shielding parameters of synthesized glassy-ceramic samples were measured in absorption geometry with Am-241, Ba-133 and Ra-226 radioactive sources. The neutron shielding parameters were theoretically calculated. The 241Am-Be fast neutron source was used to measure the equivalent dose of neutron absorption. At an incident photon energy of 74.8 keV, the mass attenuation coefficient of the tungsten oxide–enriched borate glassy-ceramic exhibited a remarkable improvement—rising by 17.98 % with the addition of 3 wt% Sm2O3 and by 11.58 % with the addition of 3 wt% La2O3. Notably, the N4 sample demonstrated a significant reduction in neutron-equivalent dose rate, reaching 19.80 % (μSv/h). The lead equivalent thicknesses (Pbeq) calculated at 356 keV were 0.02397 cmPb for N0, 0.0391 cmPb for N1, 0.0403 cmPb for N4, and 0.0389 cmPb for N7. When benchmarked against the undoped N0 sample, the N4 and N7 compositions exhibited reductions in Pbeq values by approximately 68 % and 62 %, respectively, indicating a marked improvement in gamma shielding efficiency. Among all tested formulations, the Sm2O3-doped variant demonstrated superior gamma-ray attenuation capability relative to the La2O3-doped glassy-ceramic. Furthermore, the N4 sample achieved an impressive thermal neutron attenuation rate of 96.46 %, underscoring its strong potential as an effective dual-purpose shielding material against both thermal neutrons and ionizing gamma radiation.
AtıfScopus1
İncele - MakaleYalnız künye2026Scopus SJRQ1Effect of Ni–Co–Cr additions on the microstructural and magnetic field–induced radiation shielding behavior of Fe–Si–B alloys
Taşgın, Yahya; Taşar, Fatih
Fe–Si–B–based amorphous metallic glasses were synthesized via powder metallurgy and arc melting, followed by alloying with 10 wt% Ni, Co, or Cr. The alloys were examined in both as-cast and heat-treated conditions to assess the combined influence of composition, thermal relaxation, and magnetic processing on their mechanical and radiation-shielding properties. Microstructural characterizations (XRD, SEM, EDS) confirmed homogeneous alloying and the presence of Fe2B, Fe0.91Si0.09, and Ni/Co/Cr-boride phases. After alloying and heat treatment, the average Vickers hardness increased from 313 HV (base Fe-Si-B) to 480 HV. All synthesized samples were exposed to a 1 T magnetic field, and their gamma-ray attenuation behavior was subsequently evaluated using a Ba-133 source (80.99–383.85 keV). After magnetic exposure, the linear attenuation coefficient (LAC) increased by ≈ 3–4% for Co-doped alloys, ≈ 2% for Ni-doped and base Fe–Si–B alloys, and < 0.5% for Cr-doped alloys, accompanied by a corresponding reduction in half-value layer (HVL) from 1.86 cm to 1.79 cm. The fast-neutron removal cross-section (ΣR) also exhibited a modest rise (≈2%). These enhancements are attributed to field-induced microstructural relaxation, including domain alignment, internal-stress reduction, and partial free-volume collapse, which subtly modify the local electron-density distribution without altering the bulk composition. Overall, the findings demonstrate that Ni–Co–Cr alloying, combined with controlled magnetic-field exposure, offers an effective and non-destructive route to enhance both the mechanical durability and γ-ray/fast-neutron shielding performance of Fe-based amorphous alloys, highlighting their potential for magnetically tunable protective coatings and advanced smart-shielding applications. In some applications, both the magnetic properties and radiation shielding properties of the material used are important. This study investigates the effects of Ni, Co, and Cr on the magnetic properties of the Fe-Si-B alloy, while also demonstrating changes in radiation shielding properties.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ1Radiation shielding performance of (SmEuYbLaEr)2TaO4 high-entropy oxide reinforced Cu matrix composites
Taşgın, Yahya; Yılmaz, Demet; Kanca, M. Sait; Kök, Mediha; Yayla, Nihal; Güler, Ömer
High-entropy oxides (HEOs) containing rare earth elements are attracting increasing interest due to their thermal stability and potential for use in radiation shielding applications. In this study, the high-entropy oxide (SmEuYbLaEr)2TaO4 was synthesized via mechanical alloying (MA) followed by calcination and incorporated into a Cu matrix at different reinforcement levels to produce volumetric composites. Structural, thermal, and microstructural analyses confirmed the successful formation of a stable HEO phase and its effective dispersion within the Cu matrix. The radiation shielding performance of the composites was experimentally evaluated over a wide range of photon energies using standard gamma-ray sources. The results showed that shielding performance depends largely on both photon energy and HEO content. Increasing the HEO concentration significantly reduced the half-value layer (HVL) while substantially increasing the mass attenuation coefficient (MAC) and radiation protection efficiency (RPE), particularly in the low- and medium-energy regions where the photoelectric effect is dominant. Among the materials studied, the Cu composite containing 20 wt% HEO exhibited the best overall shielding performance. These results demonstrate that (SmEuYbLaEr)2TaO4 is an effective additive for improving the radiation shielding capability of Cu-based composites and highlight its potential for advanced radiation protection applications.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ2Investigation of the Mechanical and Metallographic Effects of Adding 2-3% Al-Ti-Mo Elements to High-Entropy CoCrFeNi Alloys
Dilek, İlhan; Taşgın, Yahya; Kanca, Muhammed Sait; Kök, Mediha; Güler, Ömer
Recently, high-entropy alloys (HEAs) have attracted significant attention due to their unique multicomponent composition and exceptional mechanical properties, such as high wear and corrosion resistance, making them superior to conventional alloys for advanced engineering applications. The effects of Al, Ti, and Mo addition on the microstructural and mechanical properties of CoCrFeNi-based HEAs were investigated. The alloys were produced via powder metallurgy and vacuum arc melting, with the addition of 2 and 3% Al, Ti, and Mo, respectively. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD) were used to perform microstructural characterization, while microhardness and wear tests were used to evaluate mechanical performance. The addition of Al and Ti enhanced the face-centered cubic phase stability and increased the hardness by improving the lattice structure. In contrast, the addition of Mo contributed to solid solution and precipitation hardening, resulting in a simpler microstructure and superior tribological performance. Among all compositions, the alloy with 3% Mo addition exhibited the highest hardness value (≈ 233.8 HV) and the lowest mass loss (4.3 mg) was observed, indicating a significant improvement in the wear resistance and mechanical strength. In conclusion, the addition of Ti and Mo to CoCrFeNi HEAs promotes solid solution, precipitation, and grain boundary hardening mechanisms, thereby enhancing microstructural integrity, hardness, and wear resistance. These findings suggest that such alloys are promising candidates for use as next-generation structural and tribological materials under demanding operational conditions.
- MakaleAçık Erişim2026Scopus SJRQ1Structural and radiation shielding properties of high-entropy rare-earth oxide-doped borosilicate glass
Güler, Ömer; Yılmaz, Demet; Kanca, Muhammed Sait; Kök, Mediha; Taşgın, Yahya
In this study, the incorporation of a high-entropy rare-earth oxide, (GdLaEuPrDyY)2O3 (RE-HEO), into a borosilicate glass matrix was investigated with the aim of improving radiation shielding performance while preserving the structural integrity of the glass. The RE-HEO was first synthesized by high-energy mechanical alloying and then introduced into the glass system at concentrations ranging from 0 to 8 wt% using a conventional melt-quenching process. The structural and microstructural properties of the prepared samples were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy combined with energy-dispersive spectroscopy (SEM–EDS). The analyses confirmed that the amorphous nature of the borosilicate glass was maintained and that the rare-earth elements were homogeneously distributed within the matrix. The radiation shielding performance was evaluated experimentally using Am-241, Ba-133, and Ra-226 gamma sources, and supported by theoretical calculations of key parameters including mass attenuation coefficient (MAC), half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), exposure buildup factor (EBF), and fast neutron removal cross-section (ΣR). The results showed that increasing RE-HEO content leads to a noticeable improvement in gamma-ray attenuation. In particular, the sample containing 8 wt% RE-HEO exhibited a MAC value of 0.131 cm2/g and an HVL of 2.03 cm at 356 keV, indicating shielding performance comparable to that of conventional lead-containing glasses. In addition, irradiation tests performed using a Co-60 gamma source revealed that the amorphous structure remains stable after exposure. Overall, the findings suggest that RE-HEO-doped borosilicate glass can be considered a promising lead-free alternative for radiation shielding applications.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ1Investigation of the structural, thermal and radiation shielding properties of (Er0.2Yb0.2Sm0.2La0.2Eu0.2)2Zr2O7 high entropy oxide reinforced tin matrix composite
Güler, Ömer; Yılmaz, Demet; Kanca, M. Sait; Kök, Mediha; Güler, Seval Hale; Taşgın, Yahya
This study investigates the structural, thermal, and radiation shielding properties of (Er0.2Yb0.2Sm0.2La0.2Eu0.2)2Zr2O7 high entropy oxide (HEO) reinforced tin (Sn) matrix composites. In the first stage of the study, HEO powders were synthesized by grinding at 350 rpm for 30 h using a solid-state method with mechanical alloying assistance, and then calcining at 1100 °C for 8 h. In the second stage, composites were produced by mixing HEO-reinforced Sn matrix materials containing 1%, 5%, and 10% reinforcement, pelleting them under 200 MPa pressure, and then sintering them at 300 °C for 3 h. In the first stage of the study, (Er0.2Yb0.2Sm0.2La0.2Eu0.2)2Zr2O7 HEO powders were synthesized using a mechanical alloying-assisted solid-state route. In the second stage, HEO-reinforced Sn matrix composites containing 1 wt%, 5 wt%, and 10 wt% reinforcement were produced. The phase formation and crystallographic structure of the synthesized powders and composites were characterized using X-ray diffraction. Thermal behavior and phase stability were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The thermal analysis results revealed dehydration and structural stabilization processes at intermediate temperatures, while crystallization of the HEO phase was observed at elevated temperatures. In addition, oxidation behavior of the Sn matrix composites was evaluated, showing that the presence of HEO particles significantly suppresses mass gain during high-temperature oxidation, indicating improved thermal stability. Finally, the radiation shielding performance of the samples was experimentally evaluated within the photon energy range of 59.54–609.2 keV using Am-241, Ba-133, and Ra-226 radioactive sources together with a Ultra-Low Energy Germanium (ULEGe) detector. The results demonstrate that the incorporation of HEO particles leads to minor, energy-dependent variations in the radiation attenuation capability of the tin matrix, influenced by the presence of high atomic number rare-earth elements and modified microstructural characteristics. The gamma radiation protection coefficient (RPC) values indicate strong attenuation in the low photon energy region, decreasing to approximately 16–19% at 609.3 keV. Moreover, the measured neutron equivalent dose rates increase from 0.054 µSv/h for pure Sn to 0.285 µSv/h for the Sn–10%HEO composite, indicating that HEO incorporation modifies the neutron interaction behavior of the Sn matrix composites.
- MakaleYalnız künye2025Scopus SJRQ2The effect of WC addition on CrMnFeCoNi high entropy alloys: crystal-micro structure, hardness and wear behavior
Taşgın, Yahya; Kanca, M Sait; Kök, Mediha; Anik, Kerem
High entropy alloys are produced by combining four or more elements in close percentage ratios. Recently, these alloys have become the preferred group due to their superior mechanical and thermal properties. In this study, tungsten carbide (WC) was doped into CrMnFeCoNi alloys at different ratios, and the effects of WC and heat treatment on the doped alloys were investigated. XRD, SEM, and EDS analyses, wear tests, and microhardness measurements were performed on the produced samples to examine their microstructural properties. When comparing the heat-treated samples with WC (3%, 5%, and 10% additions) to the untreated samples, it was found that the average hardness values of the heat-treated samples were higher. Although the grain structures of the samples, as observed through XRD, SEM, and EDS, were preserved, their ratios were altered, and the wear tests revealed that the mass losses of the heat-treated samples increased.
- MakaleAçık Erişim2025Scopus SJRQ2Investigation of the effect of the metallographic properties of vertical and horizontal cylinders made of ferrochrome with different contents on heat transfer by natural convection
Kahraman, Gökhan; Taşgın, Yahya
In this study, ferrochrome materials containing elements with different content ratios were manufactured into six-cylinder specimens, 13 mm in diameter and 16 mm in length, and heated in a furnace up to 500 °C. The heated cylinders were removed and left to cool in vertical and horizontal positions in a 16 °C environment. The temperatures were recorded using thermal cameras at certain intervals while the materials cooled down. The six specimens, whose metallographic differences were identified using SEM and XRD analysis devices, were placed vertically and horizontally, and their heat transfer by natural conviction was noted. In the calculations, each specimen’s Nusselt and Rayleigh numbers were identified based on time and then compared. The fastest cooling among the specimens occurred in the ferrochromium material with 55.93% Cr, 31.11% Fe, 11.56% C, 0.48% Si, 0.83% O, and 0.09% Al compound ratios, both in vertical and horizontal positions. Additionally, since the Nusselt number of the horizontal cylinders remained below one based on their position, their natural convection flows were not initiated. The cooling in the horizontal cylinders occurred via conduction.
- MakaleAçık Erişim2025Scopus SJRQ2PCL/chitosan composite films enhanced with Bi2O3 in nuclear shielding applications: Irradiation resistance, thermal and structural properties
Yılmaz, Demet; Pekdemir, Mustafa Ersin; Dik, Gamze; Selçuk Pekdemir, Sibel; Ulu, Ahmet; Taşgın, Yahya; Ateş, Burhan
In this work, irradiation resistance, thermal, and structural characteristics of Bi2O3-reinforced poly ε-caprolactone/chitosan composites for nuclear shielding applications were studied. PCL/CTS/Bi2O3 composite films were prepared by using different amounts of Bi2O3 (0.5%–4.0% (w/v)). The radiation shielding parameters of the synthesized composite films were both experimentally and theoretically measured at the high energy region. The equivalent dose rates of the prepared film samples were measured using a fast neutron source. Also, to determine the irradiation resistance, the samples were irradiated with Am-241 and Co-60 sources for 30 days. The MFP values at 80.99 keV changed by approximately 61% in samples PCL/CTS and PCL/CTS/4% Bi2O3. The results show that Bi2O3 content increases the gamma shielding abilities in PCL/CTS films. According to TGA results, the thermal stability of the polymer composite films is increased by the addition of Bi2O3 to the PCL/CTS blend film. The results show that PCL/CTS composite materials can be used as protective coating materials for nuclear shielding. Highlights: PCL/CTS/Bi2O3 composite films were prepared by the solvent casting method. The thermal stability of the composite films increased by increasing the Bi2O3 amount. Bi2O3 increased the LAC and MAC values of the composite films. PCL/CTS/Bi2O3 composite films have a neutron shielding effect.
AtıfScopus5WoS5İncele - MakaleAçık Erişim2025Scopus SJRQ2Tungsten carbide-based shape memory biopolymer nanocomposites as a promising new gamma radiation shielding material
Pekdemir, Mustafa Ersin; Yılmaz, Demet; Selçuk Pekdemir, Sibel; Taşgın, Yahya; Ekmen, Busenur
In this study, structural, thermal and radiation shielding properties of Polylactic acid (PLA)/polyhydroxyalkanoates (PHAs)/Tungsten Carbide (WC) nanocomposite films were investigated. PHA/PLA/WC composite films were prepared by using different amounts of WC (5%, 10%, 18%, 28%). Characterization of the composite films was carried out by Attenuated Total Reflection Infrared Spectroscopy (ATR-IR), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The linear and mass attenuation coefficients (LAC and MAC), mean free path (MFP), Half-Value Layer (HVL), Tenth Value Layer (TVL), effective atomic numbers (Zeff), and effective electron densities (Nel) of the synthesized composite films were experimentally measured from 53.16 to 383.85 keV. Also, the neutron equivalent dose rates for the prepared film samples were determined. Exposure buildup factor (EBF) and fast neutron removal cross section (ΣR) were theoretically calculated. The particle shielding characteristics of the composite films were evaluated. The MFP values at 356.01 keV are 8.211 cm, 7.772 cm, 7.360 cm, 6.710 cm and 5.942 cm for PLA/PHA, PLA/PHA/5%WC, PLA/PHA/10%WC, PLA/PHA/18%WC and PLA/PHA/28%WC, respectively. It was observed that an increase in WC content enhances the gamma shielding abilities in PHA/PLA films. The results revealed that PHA/PLA/WC composite materials can be used as protective coating materials.
AtıfScopus5WoS5OpenAlex6İncele - 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 - 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 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 - MakaleYalnız künye2024Scopus SJRQ1Effect of Zr content on microstructure and wear behavior of Al-Si-Cu-Ni Mg-Zrx alloy
Taşgın, Yahya; Gök, Mehmet
In this study, the effect of zirconium addition (1, 1.5, 2 wt%) on the microstructural morphology and wear behavior of Al-Si-Cu-Ni-Mg alloys, known as light metals in which intermediate phases solidify rapidly at high temperatures, was investigated. The study aimed to obtain a stronger material by modifying the Al81Si12Cu4Ni2Mg alloy. It was observed that the Zr added to the alloy was homogeneously distributed throughout the samples. Aluminum and silicon formed compounds with zirconium (Al3Zr and ZrSi2), leading to the formation of a thinner and stronger structure. With the heat treatment applied to the aluminum alloys, the structure became more ductile. Additionally, as a result of Zr addition, microhardness increased, and wear values improved. Graphical abstract: (Figure presented.)
AtıfScopus2WoS2OpenAlex5İncele - MakaleYalnız künye2024Scopus SJRQ2Evaluating the metallographic properties and performance of heat transfer by natural convection of graphene-coated glass used for heating
Kahraman, Gökhan; Taşgın, Yahya
In this study, a decorative electric heater was manufactured to reduce carbon emissions related to residential and office heating, and this heater was metallographically evaluated. In addition, the heating performance of the manufactured plate was investigated by examining its heat transfer capacity by natural convection. For this purpose, the surface of the tempered glass plate was coated with graphene by spraying to improve its electrical and heat conduction properties. Copper strips were attached to both sides of the plate to allow for an electric current. The plate was connected to mains electricity, and its change in surface temperature over time was measured. Using the measured temperature values, the heat transfer rate by natural convection on the plate surface was calculated. As a result of the calculations, it was determined that the graphene-coated tempered glass plate reached a heating performance of 40 watts after 2400 s of electrical energy supply. This value can be increased by increasing the heat transfer surface area. This study, taking advantage of the excellent thermophysical properties of graphene, will contribute to other studies conducted in this field.
AtıfScopus2WoS2OpenAlex2İncele - MakaleYalnız künye2024Scopus SJRQ1Effects of Er2O3 contribution on microstructure and mechanical properties of high entropy and dual phase alloys
Taşgın, Yahya; Malkoç, Aziz; Kanca, M. Sait
The study aimed to look at the differences between a high entropy alloy and a dual phase high entropy alloy with high iron and Mn content. It also wanted to find out what happened when a small amount of the rare earth element erbium oxide (Er2O3) was added to these alloys, especially on the mechanical and microstructure of the alloy. The first step in this study was to get 99 % pure metal powders, which were then made by dividing the powders into 30 g of equal weight. The powders were mixed evenly and then pressed into 10-g blocks under 6 tons of pressure. They were then set up to be melted in an arc. Four of the eight samples that were melted in an arc under vacuum were treated with heat. The four different compositions were then turned into small metallographic samples for SEM, EDX, Mapping, XRD, and microhardness tests. The study's imaging and analysis processes were also carried out. After that, SEM images were taken at various magnifications (100X, 500X, 1000X, 2500X, and 5000X), and EDS and XRD analyses were done on different structures found in these images. These analyses were based on literature research about the clarity of the metallographic images in the alloy, which showed the study's metallographic differences. The samples were put through microhardness and wear tests to see which one was stronger and less worn. The dual phase high entropy alloy (A2) was stronger and less worn than the high entropy alloy (A1). Er2O3 had little effect on the alloys' mechanical properties or microstructure. The heat treatment that was done to the samples helped the metallographic structure. In terms of physics, it didn't change the hardness much, but it did make the material wear less quickly.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2023Doğal Elyaf Takviyeli (Jüt-Keten-Kenevir) Kompozit Malzemelerin Mekanik ve Metalografik Olarak İncelenmesi
Taşgın, Yahya; Kandemir, Seçkin
Teknolojinin gelişmesiyle birlikte özellikle polimer esaslı saf haldeki malzemelerin yetersiz kalmasından dolayı kompozit malzemeler geliştirilmiş ve zamanla kullanım alanları çoğalmıştır. Son yıllarda artan çevre bilincinin getirdiği üretimde sürdürülebilirlik ve yenilenebilir, çevre dostu kompozitlerin kullanımını giderek yaygınlaşmaktadır. İçeriğindeki malzemelerden en az birisinin doğal olması ile tanımlanan biyokompozitlerin, alternatiflerine kıyasla çok daha çevre dostu olmalarına karşın, hidrofilik yapıda olmaları ve mekanik özelliklerinin zayıf olması sebebiyle sanayide kısıtlı alanda kullanılmaktadır. Bu çalışmada takviye malzemesi olarak kullanıla bilirliğini ortaya koymak için jüt, keten ve kenevir den oluşan doğal lif takviyeli epoksi kompozitlerin (NFRC) mekanik ve metalografik açıdan ortaya koyduğu farkındalıklar incelenmiştir. Üretim yöntemi olarak vakum destekli reçine transfer kalıplama (VDRTK) metodu kullanılmıştır. Metalografik olarak incelediğimizde; doğal liflerin yapı içerisinde yer alması ve epoksinin ara yüzeylere nüfuziyeti açısından problem oluşturmadığı görülmüştür. Çekme testleri, kompozitler arasında farklı mekanik davranışları ortaya çıkarmıştır; keten kompoziti en yüksek çekme mukavemetini (75,56 MPa) jüt ve kenevirin ise ketene kıyasla düşük çekme mukavetine sahip olduğu görülmektedir. Endüstriyel olarak üretilen yapay elyaflara (Cam elyafı) kıyasla mekanik ve mikro yapı açısından zayıf görünse de özellikle karmaşık yapılı parçaların üretiminde nüfuziyet ve ara bölgelere yerleşebilecek olmasından kaynaklı daha kullanışlı olduğu ortaya çıkmıştır.
AtıfOpenAlex1TR Dizin1
İncele - MakaleAçık Erişim2022Scopus SJRQ2Investigation of the Effects of Deformation Aging Applied to AA 7075 Aluminum Alloy on Mechanical and Metallographic Properties
Taşgın, Yahya; Ergin, Ramazan
Aging is quite important in improving the mechanical properties of aluminum alloys. One of the most widely used Al alloys is AA7075 aluminum alloy. Since AA7075 aluminum alloys contain aluminum-zinc-magnesium-copper, various aging processes have been applied to improve their mechanical qualities, and as a result, they have become commercially available. When this aluminum alloy series with increased strength is subjected to any thermal effect in industrial use, the loss of mechanical properties can be reduced by applying deformation aging. In this study, the effect of deformation aging on the mechanical properties of commercially available aluminum alloy has been determined and the relationship between mechanical properties and microstructure examined. Deformation aging was applied to 7075 Al alloy in our study by cooling in air, water and oil at temperatures of 120–180 °C for 2–24 hours. Structural differences were revealed by examining the effects of heat treatment on the mechanical properties and machinability properties of the alloy. As a result of the study, it was observed that metallographic precipitation occurred in the AA7075 Al alloy, and accordingly, intermetallic phases were formed. It is thought that various nanoscale fine precipitates occurring in the matrix of this alloy can also prevent dislocation movements. The study has positive effects on the mechanical properties of the material.
AtıfScopus9WoS6OpenAlex8İncele - MakaleAçık Erişim2021The Investigation of Production Errors and Remedies Arising from the Mold and Material Used in the Plastic Injection Production Line
Taşgın, Yahya; Gökkoruk, Ali
Plastic injection molding is widely used in all areas of the industry. The most important reason for this is that seamless plastic products in desired shapes and sizes can be easily produced with injection molds. Plastic products are exposed to many different parameters during molding. Therefore, it is aimed to create correct production methods by seeing the effect of molding parameters. The purpose of this study was to determine the fast and correct method and minimizing the errors by detecting the manufacturing defects that may occur during the production of materials with different properties with plastic injection machines beforehand. As a result of this study, the problems caused by the air remaining in the mold during the production phase, the problems caused by the turbulence that may occur during the flow of the liquid raw material, the problems that occur in the areas where the flow paths overlap, the reasons for product loss, especially in thin-section parts, the adhesion of the part to the female mold, the product with burr, as well as problems such as distortion and gaps were determined and solutions were provided.
AtıfOpenAlex2TR Dizin1İncele - MakaleYalnız künye2021Scopus SJRQ1Crack failure in hydrodynamically lubricated bearings: A case study hydraulic turbine
Taşgın, Yahya; Kahraman, Gökhan
This study investigates the trunnion crack of a 50 MW hydraulic turbine in the generator guide bearing. The crack area has been examined metallographically and the fixing method for the the trunnion crack has been explained. Result of the study shows that the reason for the formation of the bearing trunnion crack can be the thermal stresses that occur during the mounting of the bearing trunnion to the turbine shaft and the material fatigue that occurs during the operation of the hydraulic turbine.
AtıfScopus9WoS7OpenAlex9İncele