Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Citation - WoS: 13Citation - Scopus: 14Microstructural, Mechanical, Tribological, and Corrosion Behavior of Ultrafine Bio-Degradable Mg/CeO2 Nanocomposites: Machine Learning-Based Modeling and Experiment(Elsevier Sci Ltd, 2023-12) Deka, Surja; Mozafari, Farzin; Mallick, AshisThe present study investigated the microstructural, mechanical, tribological, and corrosion behavior of near-dense and low-volume fraction magnesium-cerium dioxide (Mg/CeO2) (x = 0.5, 1, and 1.5 vol.%) nanocomposites synthesized by in-situ hot extrusion assisted powder metallurgy (PM) process. Results showed a significant improvement in wear resistance for Mg/CeO2 nanocomposite compared to monolithic Mg at varied applied loads. Microindentation tests were performed to access the Vickers microhardness homogeneity along the extrusion direction. The corrosion analysis revealed that introducing ceria nanoparticles enhanced Mg's corrosion resistance and expedited the development of an apatite layer on the surface, providing enhanced protection. A feedforward neural network and Long Short-Term Memory (LSTM) network were also developed to characterize nanocomposites' wear and corrosion behavior.Article Hydrogen Susceptibility of Al 5083 Under Ultra-High Strain Rate Ballistic Loading(Walter de Gruyter Gmbh, 2024-09-25) Baltacioglu, Mehmet Furkan; Mozafari, Farzin; Aydin, Murat; Cetin, Baris; Oktan, Aynur Didem; Teoman, Atanur; Bal, BurakThe effect of hydrogen on the ballistic performance of aluminum (Al) 5083H131 was examined both experimentally and numerically in this study. Ballistics tests were conducted at a 30 degrees obliquity in accordance with the ballistic test standard MIL-DTL-46027 K. The strike velocities of projectiles were ranged from 240 m s-1 to 500 m s-1 level in the room temperature. Electrochemical hydrogen charging method was utilized to introduce hydrogen into material. Chemical composition of material was analyzed using energy dispersive X-ray (EDX) analysis. Instant camera pictures were captured using high-speed camera to compare H-uncharged and H-charged specimen ballistics tests. The volume loss in partially penetrated specimens were assessed using the 3D laser scanning method. Microstructural examinations were conducted utilizing scanning electron microscopy (SEM). It was observed that with the increased deformation rate, the dominance of the HEDE mechanism over HELP became evident. Furthermore, the experimental findings were corroborated through numerical methods employing finite element analysis (FEM) along with the Johnson-Cook plasticity model and failure criteria. Inverse optimization technique was employed to implement and fine-tune the Johnson-Cook parameters for H-charged conditions. Upon comparing the experimental and numerical outcomes, a high degree of consistency was observed, indicating the effective performance of the model.Article Citation - WoS: 9Citation - Scopus: 9A Comprehensive Experimental and Modeling Study of the Strain Rate- and Temperature-Dependent Deformation Behavior of Bio-Degradable Mg-Ceo2 Nanocomposites(Elsevier Sci Ltd, 2024-02) Deka, Surja; Mozafari, Farzin; Mallick, AshisA comprehensive study was undertaken on the temperature-dependent and strain rate-sensitive deformation behavior of near-dense low-volume fraction magnesium-cerium dioxide (Mg-CeO2) nanocomposites synthesized by powder metallurgy technique. The process involved ball milling of elemental powders -> cold compaction -> sintering in an inert atmosphere, and in-situ hot extrusion. The Mg-CeO2 nanocomposites displayed strain rate and temperature sensitivity, exhibiting higher yield strength, superior compressive characteristics, greater hardness, and improved ductility compared to pure Mg and most commercial Mg alloys. Furthermore, a thorough micro-structural investigation was conducted to characterize the distributions of ceria nanoparticles, grain refinement degree, ceria-magnesium interface, formation of deformation twins and interfacial bonding between the reinforcement and matrix. The present study has proposed two modeling approaches, the Johnson-Cook (J-C) constitutive model and a machine learning-assisted model, to predict the mechanical behavior of monolithic Mg and Mg-CeO2 nanocomposites. The models effectively explained the deformation behavior under various strain rates and temperatures.