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: 14The Effect of Strain Rate on the Hydrogen Embrittlement Susceptibility of Aluminum 7075(ASME, 2022-11-22) Baltacioglu, Mehmet Furkan; Cetin, Baris; Bal, BurakThe effects of changing the strain rate regime from quasi-static to medium on hydrogen susceptibility of aluminum (Al) 7075 were investigated using tensile tests. Strain rates were selected as 1 s(-1) and 10(-3) s(-1) and tensile tests were conducted on both hydrogen uncharged and hydrogen charged specimens at room temperature. Electrochemical hydrogen charging method was utilized and the diffusion length of hydrogen inside Al 7075 was modeled. Material characterizations were carried out by X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) and microstructural observations of hydrogen uncharged and hydrogen charged specimens were performed by scanning electron microscope (SEM). As opposed to earlier studies, hydrogen embrittlement (HE) was more pronounced at high strain rate cases. Moreover, hydrogen enhanced localized plasticity (HELP) was the more dominant hydrogen embrittlement mechanism at slower strain rate but coexistence of hydrogen enhanced localized plasticity and hydrogen enhanced decohesion was observed at a medium strain rate. Overall, the current findings shed light on the complicated hydrogen embrittlement behavior of Al 7075 and constitute an efficient guideline for the usage of Al 7075 that can be subject to different strain rate loadings in service.Article Citation - WoS: 32Citation - Scopus: 32A Detailed Investigation of the Effect of Hydrogen on the Mechanical Response and Microstructure of Al 7075 Alloy Under Medium Strain Rate Impact Loading(Pergamon-Elsevier Science Ltd, 2020-09) Bal, Burak; Okdem, Bilge; Bayram, Ferdi Caner; Aydin, MuratEffects of hydrogen and temperature on impact response and corresponding microstructure of aluminum (Al) 7075 alloy were investigated under medium strain rate impact loading. The specimens were subjected to impact energy of 12 J and 25 J, corresponding to impact velocities of 2.13 m/s and 3.08 m/s, respectively. These energy levels were decided after a couple of impact tests with different impact energy values, such as 6 J, 10 J, 12 J, 25 J. The experiments were conducted at five different temperatures. Electrochemical charging method was used for hydrogen charging. Microstructural observations of hydrogen uncharged and hydrogen charged specimens were carried out by scanning electron microscope. Hydrogen changed the crack propagation behavior of Al 7075 alloy depending on the temperature. Coexistence of several hydrogen embrittlement mechanisms, such as hydrogen enhanced decohesion (HEDE) and hydrogen enhanced localized plasticity (HELP) were observed under impact loading. The impact response of Al 7075 was significantly deteriorated by the hydrogen charging and changing temperature affected the absorbed energy of hydrogen-charged specimens. In addition, molecular dynamics simulations were conducted to uncover the atomistic origin of hydrogen embrittlement mechanisms under impact loading. In particular, hydrogen decreased the cohesive energy and enhanced the average dislocation mobility. Therefore, the experimental results presented herein constitute an efficient guideline for the usage of Al alloys that are subject to impact loading in service in a wide range of temperatures. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.