The golden alloy Cu5Zn5Al1Sn: effect of immersion time and anti-corrosion activity of cysteine in 3.5 wt% NaCl solution

The effect of cysteine on the corrosion characteristics of Cu5Zn5Al1Sn alloy in 3.5 wt% NaCl solution has been studied by electrochemical and surface characterization techniques in various immersion times. The results of electrochemical impedance spectroscopy (EIS) revealed that the degradation of Cu5Zn5Al1Sn alloy occurred in 3.5 wt% NaCl and was aggravated with increasing immersion time. The results of inhibition efficiency calculated from EIS data showed that cysteine can act as an effective anti-corrosion substance, which was also proved by the less eroded morphology of the alloy surface observed on scanning electron microscopy (SEM). Furthermore, the elemental analysis of alloy surfaces was investigated by Raman, electron dispersion spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS), which confirmed the presence of S and N species. An adequate adsorption isotherm and inhibition mechanism was also suggested based on EIS results.