The magnesium alloys are considered to be the best structural materials,because of their advantageous weight to strength ratio.But,the limitation in their real field applications lies on the fact that magnesium alloys...The magnesium alloys are considered to be the best structural materials,because of their advantageous weight to strength ratio.But,the limitation in their real field applications lies on the fact that magnesium alloys are highly susceptible for corrosion.The corrosion behaviour of AZ31 alloy was investigated by electrochemical methods in sodium chloride and sodium sulphate of different concentrations at different temperatures.The corrosion rate was monitored by potentiodynamic polarization technique and electrochemical impedance spectroscopy method.The surface morphology and surface composition of the freshly polished surface of the alloy was compared with that of the corroded surface by recording their SEM images and EDS,respectively.The results showed that the corrosion rate of AZ31 alloy increased with the increase in the temperature of the medium and also with the increase in the salt concentration of the medium.The activation parameters for the corrosion process were calculated and interpreted.展开更多
The magnesium alloy ZE41 encompasses a wide spectrum of applications as a structural material.An extremely high susceptibility to corrosion limits widespread utility of ZE41.In the present study it has been attempted ...The magnesium alloy ZE41 encompasses a wide spectrum of applications as a structural material.An extremely high susceptibility to corrosion limits widespread utility of ZE41.In the present study it has been attempted to understand the corrosion behaviour of ZE41 alloy employing electrochemical techniques like Tafel extrapolation and electrochemical impedance spectroscopy(EIS)in aqueous salt solutions containing mixture of sodium chloride and sodium sulphate over a varying range of electrolyte concentrations and solution temperatures.The morphology of the metal surface has been established by means of scanning electron microscopy(SEM).The results indicate that the rate of corrosion of ZE41 alloy increases with the increase in temperature and ionic concentration of the medium.The results of corrosion rates at varying temperatures have been utilized in the calculation of activation parameters such as activation energy,enthalpy of activation and entropy of activation for the corrosion process.展开更多
The effects of sulfate ion concentration,temperature and medium pH on the corrosion of Mg–Al–Zn–Mn alloy in 30%aqueous ethylene glycol solution have been investigated by electrochemical techniques such as potentiod...The effects of sulfate ion concentration,temperature and medium pH on the corrosion of Mg–Al–Zn–Mn alloy in 30%aqueous ethylene glycol solution have been investigated by electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy methods.Surface morphology of the alloy was examined before and after immersing in the corrosive media by scanning electron microscopy(SEM)and energy dispersion X-ray(EDX)analysis.Activation energy,enthalpy of activation and entropy of activation were calculated from Arrhenius equation and transition state theory equation.The obtained results indicate that,the rate of corrosion increases with the increase in sulfate ion concentration and temperature of the medium and decreases with the increase in the pH of the medium.展开更多
The corrosion behavior of Mg-Al-Zn-Mn(GA9)alloy in sodium sulfate solutions was studied over a range of concentrations and solution temperatures at different pH conditions by electrochemical techniques like Tafel extr...The corrosion behavior of Mg-Al-Zn-Mn(GA9)alloy in sodium sulfate solutions was studied over a range of concentrations and solution temperatures at different pH conditions by electrochemical techniques like Tafel extrapolation and electrochemical impedance spectroscopy(EIS).The studies were carried out in solutions with sodium sulfate concentrations 0.1M,0.5M,1M,1.5M and 2M;and at five different temperatures of 30,35,40,45 and 50℃ in a pH range of 3-12.As per the experimental data,the corrosion rate of the alloy increased with the increase in temperature,and also with the increase in concentration of sodium sulfate in the medium.It was observed that the rate of corrosion decreased with the increase in pH.The activation parameters like activation energy,enthalpy of activation and entropy of activation for the corrosion process were calculated.The surface morphology of the alloy was examined before and after corrosion using scanning electron microscopy(SEM).展开更多
文摘The magnesium alloys are considered to be the best structural materials,because of their advantageous weight to strength ratio.But,the limitation in their real field applications lies on the fact that magnesium alloys are highly susceptible for corrosion.The corrosion behaviour of AZ31 alloy was investigated by electrochemical methods in sodium chloride and sodium sulphate of different concentrations at different temperatures.The corrosion rate was monitored by potentiodynamic polarization technique and electrochemical impedance spectroscopy method.The surface morphology and surface composition of the freshly polished surface of the alloy was compared with that of the corroded surface by recording their SEM images and EDS,respectively.The results showed that the corrosion rate of AZ31 alloy increased with the increase in the temperature of the medium and also with the increase in the salt concentration of the medium.The activation parameters for the corrosion process were calculated and interpreted.
文摘The magnesium alloy ZE41 encompasses a wide spectrum of applications as a structural material.An extremely high susceptibility to corrosion limits widespread utility of ZE41.In the present study it has been attempted to understand the corrosion behaviour of ZE41 alloy employing electrochemical techniques like Tafel extrapolation and electrochemical impedance spectroscopy(EIS)in aqueous salt solutions containing mixture of sodium chloride and sodium sulphate over a varying range of electrolyte concentrations and solution temperatures.The morphology of the metal surface has been established by means of scanning electron microscopy(SEM).The results indicate that the rate of corrosion of ZE41 alloy increases with the increase in temperature and ionic concentration of the medium.The results of corrosion rates at varying temperatures have been utilized in the calculation of activation parameters such as activation energy,enthalpy of activation and entropy of activation for the corrosion process.
文摘The effects of sulfate ion concentration,temperature and medium pH on the corrosion of Mg–Al–Zn–Mn alloy in 30%aqueous ethylene glycol solution have been investigated by electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy methods.Surface morphology of the alloy was examined before and after immersing in the corrosive media by scanning electron microscopy(SEM)and energy dispersion X-ray(EDX)analysis.Activation energy,enthalpy of activation and entropy of activation were calculated from Arrhenius equation and transition state theory equation.The obtained results indicate that,the rate of corrosion increases with the increase in sulfate ion concentration and temperature of the medium and decreases with the increase in the pH of the medium.
文摘The corrosion behavior of Mg-Al-Zn-Mn(GA9)alloy in sodium sulfate solutions was studied over a range of concentrations and solution temperatures at different pH conditions by electrochemical techniques like Tafel extrapolation and electrochemical impedance spectroscopy(EIS).The studies were carried out in solutions with sodium sulfate concentrations 0.1M,0.5M,1M,1.5M and 2M;and at five different temperatures of 30,35,40,45 and 50℃ in a pH range of 3-12.As per the experimental data,the corrosion rate of the alloy increased with the increase in temperature,and also with the increase in concentration of sodium sulfate in the medium.It was observed that the rate of corrosion decreased with the increase in pH.The activation parameters like activation energy,enthalpy of activation and entropy of activation for the corrosion process were calculated.The surface morphology of the alloy was examined before and after corrosion using scanning electron microscopy(SEM).
