Sürdürülebilir Kalkınma Amaçları

• 18
• 5
• 3
• 1

• MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/1455
  Comparative Microstructural, Mechanical, and Tribological Evaluation of Cu Matrix Composites Reinforced with B4C, B, Cr, Co, Al2O3, and Graphite via Powder Metallurgy

  Macit, Cevher Kursat; Gürgenç, Turan; Aksakal, Bunyamin; Aslan, Naim

  Copper and its alloys are widely used in electrical, automotive, aerospace, and energy applications because of their excellent thermal and electrical conductivity. However, the low hardness and poor wear resistance of pure Cu limit its use under tribologically demanding sliding conditions. In this study, Cu matrix composites reinforced with 1 wt.% boron carbide (B4C), boron (B), chromium (Cr), cobalt (Co), alumina (Al2O3), and graphite (Gr) were fabricated by powder metallurgy and comparatively evaluated under identical processing and testing conditions. Phase constitution and microstructural characteristics were analyzed by XRD, SEM, and EDS, while mechanical and tribological behavior was assessed by Vickers hardness and dry sliding wear tests. All reinforcements improved the hardness of the Cu matrix compared with unreinforced Cu. The hardness increase followed the order Cu–B4C (68.91%) > Cu–B (66.43%) > Cu–Gr (63.97%) > Cu–Al2O3 (61.79%) > Cu–Cr (42.69%) > Cu–Co (36.04%). Dry sliding wear tests, performed under a 10 N normal load, 0.05 m s−1 sliding speed, and 1000 m sliding distance against a 316L stainless-steel ball, showed that all reinforced composites exhibited lower mass loss and more stable sliding behavior than pure Cu. Among all samples, Cu–B4C displayed the best wear performance, with a 154.8% improvement in wear resistance relative to pure Cu. SEM analysis of the worn surfaces revealed that reinforcement addition reduced severe plastic deformation, groove formation, and delamination, leading to a more stable wear regime. Graphite- and boron-containing composites benefited from interfacial lubrication and contact stabilization, whereas B4C and Al2O3 improved wear resistance through rigid-particle strengthening and enhanced load-bearing capacity. By comparing ceramic, metalloid, metallic, oxide, and solid-lubricating reinforcements at the same low addition level and under identical processing and testing conditions, this study provides a reinforcement-selection framework for Cu-based composites requiring improved hardness and dry-sliding durability.

  AtıfScopus2·WoS2·OpenAlex2

  İncele
• MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/1325
  Multi-functional GeAg- and TiO2-modified diamond-like carbon thin film device: structure, surface properties, photoresponse, photosensitivity, and biological performance

  Aslan, Naim; Şükrü Kurt, Mustafa; Mehmet Koç, Mümin; Yilmazer, Yasemin; Coskun, Burhan; Aksakal, Bünyamin

  DLC films represent a promising class of materials that can be used in various applications due to their optical, optoelectronic, tribological, and biomedical characteristics. In this work, GeAg- and TiO2-modified DLC thin films were prepared using the magnetron sputtering method under ultrahigh vacuum conditions. DLC thin film characteristics and addition of GeAg and TiO2 into the DLC structure were confirmed and subsequently assessed via scanning electron microscopy (SEM), atomic force microscopy, energy dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, and Raman spectroscopy. DLC thin film thicknesses were determined via SEM and found to be 235 nm and 380 nm for DLC/TiO2 and DLC/GeAg thin films, respectively. Contact angle and surface wettability analyses were performed for uncoated glass, GeAg- and TiO2-modified DLC thin films. The antibacterial properties of the DLC films were assessed for E. coli and S. aureus. The biocompatibility of these same films was confirmed using the L929 cell line, where no toxic effect was evidenced. To elucidate the optical characteristics of the thin films, a UV–vis spectrum was obtained, and band gap energies were proposed using these data. Photoresponse characteristics of the DLC thin films were assessed under varying illumination using current–time plots. It could be seen that DLC thin films’ responsiveness to light was dependent on illumination intensity. The results demonstrate that nanostructures are good candidates for multifunctional applications exhibiting good antibacterial and photoresponsive characteristics with outstanding biocompatibility.

  İncele
• MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/1129
  Thickness- and Binder-Chemistry-Dependent Structural, Mechanical, and Tribological Performance of HVOF-Sprayed WC-Co and WC-Co-Cr Coatings on High-Speed Steel

  Macit, Cevher Kursat; Aksakal, Bünyamin; Ayık, Merve; Gürgenç, Turan; Aslan, Naim

  High-velocity oxy-fuel (HVOF) spraying was used to deposit WC-Co and WC-Co-Cr coatings on high-speed steel in order to determine how binder chemistry and coating thickness jointly control load support, friction, and dry sliding wear resistance. Nominal 50 and 100 µm coatings were compared within the same substrate framework by XRD, FT-IR, SEM/EDX, cross-sectional image analysis, Vickers hardness testing, dry sliding wear testing, and post-wear SEM/EDX. The coatings retained WC as the dominant crystalline phase, while weak overlapping features were associated with binder-rich regions and limited decarburization products. Cross-sectional observations confirmed continuous coating build-up close to the nominal thicknesses and low apparent dark-feature/porosity fractions. All WC-based coatings increased the effective hardness and reduced mass loss relative to uncoated HSS. Among the tested conditions, WC-Co-Cr-100 provided the highest effective hardness and the lowest mass loss after 1000 m sliding, whereas WC-Co-100 produced the lowest mean coefficient of friction. The results show that low friction and high wear resistance are not governed by identical mechanisms: WC-Co favours interfacial shear reduction, while the thicker Cr-containing coating provides superior resistance to material removal through improved carbide retention, binder stability, and coating-scale load support.

  İncele
• MakaleYayıncıda açık erişim2026Scopus SJRQ3/r/munzur/1095
  Interfacial Polarization in PS/Sm2O3 Nanocomposite Films for Low-Loss Frequency-Dependent Dielectric Application

  Güner, Melek; Özkan, Betül Çiçek; Gürgenç, Ezgi; Macit, Cevher Kürşat; Aslan, Naim; Gurgenc, Turan

  Rare-earth oxide nanoparticles offer a strategy to tune dielectric films via interfacial polarization while maintaining low-loss insulating behavior. Here, polystyrene/samarium oxide (PS/Sm2O3) nanocomposite films containing 0, 1, 3, 5, and 10 wt.% Sm2O3 were fabricated by solvent casting and evaluated as a low-loss dielectric for frequency-sensitive electronic applications. FTIR, XRD, SEM/EDX, and XPS confirmed successful Sm2O3 incorporation, preservation of the PS structure, formation of PS/Sm2O3 interfacial regions, and Sm3+/Sm–O species. XRD revealed amorphous PS with increasingly intense crystalline Sm2O3 reflections, whereas SEM/EDX showed relatively uniform filler distribution at low and moderate loadings and partial agglomeration at 10 wt.%. Dielectric spectroscopy at room temperature from 1 kHz to 1 MHz showed a frequency-dependent response governed by interfacial polarization and limited charge transport. At 1 kHz, the dielectric constant increased from 8.67241 ± 0.00280 for pure PS to 10.13061 ± 0.00641 for PS-10, while the loss tangent remained low (∼ 0.068). The dielectric loss increased moderately from 0.59535 ± 0.00236–0.69194 ± 0.00710, and AC conductivity rose from (3.31202 ± 0.01314) × 10−10 to (3.84935 ± 0.03948) × 10−10 S cm−1. These results indicate interface-controlled dielectric enhancement without conductive percolation, highlighting PS/Sm2O3 films for capacitor dielectric layers, insulating films, flexible electronics, and frequency-sensitive dielectric technologies.

  İncele
• MakaleYalnız künye2025Scopus SJRQ2/r/munzur/2323
  Green synthesis of environmentally friendly Ag/AgCl nanoparticles for use as solid phase extraction materials

  Kurnaz Yetim, Nurdan; Hasanoğlu Özkan, Elvan; Aslan, Naim; Koç, Mümin Mehmet; Nartop, Dilek; Özcan, Cemile

  Green synthesis is a prominent procedure used to easily and environmentally friendly fabricate nanostructures and nanoparticles (NPs), without complex instrumentation, intricate procedures, and harmful chemicals. This study investigated the green synthesis of silver NPs (AgNPs), with Aronia melanocarpa fruit extract as the reducing agent. Following synthesis optimization, AgNPs were characterized using a range of analytical techniques, including UV–Vis, XRD, SEM-EDX, BET, and TEM analyses. Based on the characterization results, an Ag/AgCl hybrid structure was formed. The Ag/AgCl NPs obtained were utilized as adsorbents to remove Cd(II) and Pb(II) heavy metals. The experimental factors that were optimized included pH (5.5), sample volume (5 mL), eluent type and concentration (2 M HNO3), adsorbent amount (5 mg), and extraction time (30 min). Under optimized conditions, the limits of detection were determined to be 9.6 and 4.8 µg/L for Pb(II) and Cd(II), respectively. These limits were established within a concentration range of 50–3,000 µg/L.

  • 
  • 
  AtıfScopus3·WoS3·OpenAlex3

  İncele
• MakaleAçık Erişim2025Scopus SJRQ1/r/munzur/1546
  Y2O3-Doped BioGlass Coatings for Ti-6Al-4V Alloy: Insights into Degradation, Bioactivity, Ion Release, Adhesion, and Corrosion Behavior

  Say, Yakup; Aslan, Naim; Cihangir, Salih; Murat, Oğuzkağan; Çaydaş, Ulaş

  The Ti-6Al-4V alloy is particularly favored for orthopedic applications. However, important issues such as corrosion resistance, biocompatibility, and ion release need to be addressed. Therefore, this study aims to enhance the corrosion resistance and biocompatibility and reduce the ion release of the Ti-6Al-4V alloy by applying Y2O3-doped bioglass bioceramic coatings. The coatings were synthesized using the sol-gel method, including pure BioGlass and BioGlass with 1, 5, and 10 wt pct Y2O3. These coatings were then evaluated for their corrosion resistance, adhesion strength, degradation behavior, bioactivity, and ion release. The results showed that all coatings exhibited homogeneous, crack-free, and porous morphologies, which are favorable for osteointegration. The addition of 10 wt pct Y2O3 to the BioGlass coating resulted in a 52 pct increment in adhesion strength, which increased from 13.72 ± 2.80 MPa for single BioGlass coatings to 20.81 ± 2.53 MPa. All samples showed degradation values lower than 1 wt pct. Single BioGlass coatings significantly enhanced the bioactivity of Ti-6Al-4V alloy. However, the addition of Y2O3 negatively impacted BioGlass bioactivity, leading to a noticeable decrease as the Y2O3 content increased. Conversely, the presence of Y2O3 negatively impacted bioactivity and corrosion resistance while increasing the release of Ti ions. Specifically, the release of Ti ions increased from 79.5 ± 0.8 ppb in uncoated samples to 253.7 ± 15.3 ppb in BG-coated samples. For 1, 5, and 10 pct Y2O3-added samples, Ti releases were measured as 192.2 ± 33.6 ppb, 168.5 ± 62.4 ppb, and 194.3 ± 54.4 ppb, respectively. This research highlights the potential of tailored BioGlass coatings to improve the performance of Ti-6Al-4V alloys in orthopedic implant applications, particularly for enhancing bone integration and reducing implant failure.

  • 
  AtıfScopus4·WoS3·OpenAlex5

  İncele
• Kitap BölümüYalnız künye2025/r/munzur/1324
  DLC coatings for optical and optoelectronic applications

  Koç, Mümin Mehmet; Aslan, Naim

  Diamond-like carbon (DLC) materials, special amorphous forms of carbon, are quite stable and durable, therefore finding applications in different industries. It baffles people from both industrial and scientific communities where tribological, mechanical, chemical, optical, and optoelectronic properties were used for various applications. DLC films were used in different optical applications regarding their optical performance. Having outstanding shear and mechanical performance and high chemical inertness makes DLC thin films a suitable candidate for optical applications and devices that work under tough conditions. Thus, they were preferred in photovoltaic devices, monitors, cameras, lenses, medical devices, fiber optic cable technologies, and illumination technologies. Their absorption, emission, and transmission characteristics were also addressed in various optical applications and studies.

  AtıfScopus4·OpenAlex1

  İncele
• MakaleAçık Erişim2025Scopus SJRQ2/r/munzur/1000
  Effects of ZrN and DLC coatings on morphostructural, corrosion, cell viability, and antibacterial properties of Ti6Al4V scaffolds

  Aslan, Naim; Aksakal, Bünyamin; Cihangir, Salih; Fidan, Ferzan; Yilmazer, Yasemin

  Lightweight and functional metallic materials are consistently favored and attract significant attention in the biomedical field. This study investigates the influence of ZrN and DLC coatings on Ti6Al4V scaffolds with varying porosities (40%, 50%, 60%) for biomedical applications. PVD-deposited coatings exhibited distinct growth mechanisms: High-resolution SEM-FIB analyses revealed columnar ZrN structures due to limited adatom mobility, while DLC formed conformal, amorphous layers via high-energy carbon species. Corrosion resistance decreased in 40% porous DLC and 60% porous ZrN-coated samples, likely due to coating defects and increased electrolyte access through open pores. ZrN coatings showed superior antibacterial activity and attributed to surface reactivity and potential ion release. In contrast, the uncoated 60% porous scaffolds demonstrated highest cell viability, suggesting that excessive coating on highly porous structures may hinder cell–material interactions. Furthermore, the cytotoxicity evaluations indicated that uncoated scaffolds exhibited the highest cell viability (77.51%) at 60% porosity after 48 hours, with ZrN coatings demonstrating better efficacy compared to DLC in the 50% and 60% porosity groups.

  • 
  AtıfScopus3·WoS3·OpenAlex3

  İncele
• MakaleAçık Erişim2024/r/munzur/5695
  Effects of Porosity and Boron Reinforcement in AISI 316L Stainless Steel for Biomedical Applications

  Aslan, Naim; Aksakal, Bunyamin; Fidan, Ferzan

  AISI 316L stainless steel (SS) is one of the most widely used biomaterials in the manufacture of implants and biomaterials. It has advantages over equivalent biomaterials such as low cost, good mechanical properties and biocompatibility. The pores found in porous biomaterials provide mechanical interlock, ensuring strong attachment of the implant to the tissue. In this study, 20%, 30% and 40% by volume of polyvinyl alcohol (PVA) and Boron powder were added into 316L powder to obtain porous SS implant. To investigate the effect of porosity and boron effect on the stainless-steel implant material, the samples produced in PVA and Boron added groups, were sintered at 1180 oC under an argon atmosphere. With the evaporation of PVA in the structure, porous and boron added samples were obtained in two groups. Finally, the samples were subjected to Brinell hardness and compression tests and analyzed by SEM, EDS and XRD. As a result of the hardness tests, the highest values were measured as 37.006, 31.32, 25.28 HB. 39.5, 34.5, 26.2 MPa strengths were measured for 20%, 30% and 40% porous samples respectively.

  • 
  AtıfOpenAlex1

  İncele
• DüzeltmeAçık Erişim2024Scopus SJRQ1/r/munzur/2103
  Correction to: Influence of Plastic Deformation and Hydroxyapatite Coating on Structure, Mechanical, Corrosion, Antibacterial and Cell Viability Properties of Zinc Based Biodegradable Alloys (Metals and Materials International, (2024), 30, 12, (3320-3337), 10.1007/s12540-024-01710-z)

  Aksakal, B.; Isın, Ege; Aslan, N.; Cihangir, S.; Sezek, S.; Yilmazer, Yasemin

  In the original version of this article, co-author ‘Yasemin Yilmazer’ name was missed to add in the author group. The correct order of author names should read as ‘B. Aksakal · Ege Isın · N. Aslan · S. Cihangir · S. Sezek, Y. Yilmazer’. The affiliation details of Yasemin Yilmazer are ‘Department of Molecular Biology and Genetics Sabahattin Zaim University, Istanbul, Turkey yaseminyilmazer14@gmail.com’. The original article has been corrected.

  İncele