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Öğe Assessment of the corrosion behaviour of untreated and chemically treated pure magnesium in simulated body fluid(Taylor & Francis Ltd, 2022) Gerengi, Hüsnü; Cabrini, Marina; Solomon, Moses M.; Kaya, ErtuğrulThe corrosion behaviour of pure Mg in simulated body fluid (SBF) and the effect of chemical treatment on the corrosion resistance property were investigated using DEIS (dynamic electrochemical impedance spectroscopy), EIS (electrochemical impedance spectroscopy), PDP (potentiodynamic polarization), SEM (scanning electron microscopy), AFM (atomic force microscope), and pH measurement techniques for 30 h. NaOH or H2O2 were utilized for the chemical treatment. The DEIS was used for the first time in the investigation of Mg corrosion in SBF. Results obtained disclosed that the chemical treatment benefitted the anticorrosion property immensely. Results from both the electrochemical and surface analysis techniques are consistent.Öğe Chemical, Electrochemical, and Surface Morphological Studies of the Corrosion Behavior of the AZ31 Alloy in Simulated Body Fluid: Effect of NaOH and H2O2 Surface Pretreatments on the Corrosion Resistance Property(Amer Chemical Soc, 2022) Gerengi, Hüsnü; Cabrini, Marina; Solomon, Moses M.; Kaya, Ertuğrul; Gritti, Luca; Yola, Mehmet LutfiMagnesium and its alloys have attracted attention for biomedical implant materials in dental and orthopedic applications because of their biodegradability and similar properties to human bones. The very high rate of degradation in the physiological systems is, however, a major setback to their utilization. Chemical modification is one of the approaches adopted to enhance the corrosion resistance property of Mg and its alloys. In this work, NaOH and H2O2 were used as a pretreatment procedure to improve the corrosion resistance of the AZ31 Mg alloy in simulated body fluid (SBF). Advanced techniques such as dynamic electrochemical impedance spectroscopy (dynamic-EIS), atomic force microscopy, and optical profilometry were used in addition to the classical mass loss, hydrogen evolution, EIS, and polarization techniques to study the corrosion resistance property of the alloy in SBF for 30 h. Results obtained show that the surface treatment significantly enhanced the corrosion resistance property of the alloy. From dynamic-EIS at 30 h, the charge transfer resistance of the untreated AZ31 Mg alloy is 432.6 omega cm(2), whereas 822.7 and 2617.3 omega cm(2) are recorded for NaOH-and H2O2-treated surfaces, respectively. H2O2 is a better treatment reagent than NaOH. The mechanism of corrosion of both untreated and treated samples in the studied corrosive medium has been discussed.Öğe Effect of Chemical Treatment on the Corrosion Behavior of Mg-2Zn-1Mn (ZM21) Magnesium Alloy(Springer, 2024) Kaya, Ertugrul; Gerengi, Husnu; Cabrini, MarinaMagnesium alloys have gained interest as biomedical implant materials in dental and orthopedic applications due to their biodegradability and similarities to human bones. However, their high rate of degradation in physiological systems poses a significant challenge for their use. To address this issue, chemical modification is being explored to improve the corrosion resistance of magnesium and its alloys. In this study, they investigated the effects of chemical modification using NaOH and H2O2 on the bioactivity and corrosion resistance of a Mg-2Zn-1Mn (ZM21) magnesium alloy in simulated body fluid (SBF) using advanced techniques such as dynamic electrochemical impedance spectroscopy (dynamic EIS), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), atomic force microscopy, and x-ray diffraction (XRD). Results obtained using DEIS measurements after 30 hours showed that the charge transfer resistance of the untreated ZM21 alloy was 229.4, 1226.8 omega cm(2) for the NaOH-treated surface, and 1066.3 omega cm(2) for the H2O2-treated surface. The study found that NaOH is more effective than H2O2 in improving the corrosion resistance of the ZM21 magnesium alloy in simulated body fluid. Additionally, the mechanism of corrosion for both untreated and treated samples in the corrosive environment was investigated and discussed in the study.Öğe A Probe into the Corrosion Behavior of a WE43B Magnesium Alloy in a Simulated Body Fluid using Dynamic Electrochemical Impedance Spectroscopy(Springer, 2023) Gerengi, Husnu; Lorenzi, Sergio; Solomon, Moses M.; Slepski, Pawel; Gratton, Sara; Cabrini, MarinaWE43B is one of the newest Mg alloys with practical application in biomedical implant technology. This work attempts to scrutinize the corrosion characteristics of WE43B alloy in a simulated body fluid (SBF) at a typical body temperature. The dynamic-electrochemical impedance spectroscopy with the capacity to track changes on surfaces in a dynamic corrosive system is used in combination with other classical techniques namely, linear polarization, EIS, and hydrogen evolution to track the corrosion pattern of the alloy in SBF for 24 h. The electrochemical results reveal a steady increase in the corrosion resistance of the alloy with immersion time reaching 1398 ohm cm2 at 24 h. This corroborates the hydrogen evolution results in which a declining trend in the corrosion rate with immersion time is observed. The corrosion rate of the alloy is in the range of 1.326-1.338 mm y-1 at 24 h. The results from the applied techniques are comparable. The surface analysis (scanning electron microscope, energy-dispersive x-ray spectroscopy, atomic force microscopy AFM) results conform with the results obtained from applied methods.Öğe Understanding the Corrosion Behavior of the AZ91D Alloy in Simulated Body Fluid through the Use of Dynamic EIS(Amer Chemical Soc, 2022) Gerengi, Hüsnü; Cabrini, Marina; Solomon, Moses M.; Kaya, ErtuğrulDynamic electrochemical impedance spectroscopy (dynamic EIS) has the capacity to track changes on surfaces in a changing corrosive system, an advantage it holds over classical EIS. We used the dynamic EIS approach to provide insight into the corrosion behavior of the AZ91D Mg alloy in simulated body fluid for 30 h at 25 degrees C. The results reveal that the impedance response of the alloy is influenced by the immersion time. Between 0 and 7 h, impedance with three time constants was obtained, whereas two-time-constant impedance spectra were obtained between 8 and 30 h of immersion. The results confirm the breakdown of the corrosion product at longer immersion times.
