Early electrochemical characteristics and corrosion behaviors of pure zinc in simulated body fluid

Abstract

• QCM technique was used to monitor the early mass change of Zn in SBF. • Pitting and preferential dissolution occurred along grain boundaries. • Localized corrosion and the corrosion rate were affected by CPF. The demand for zinc (Zn) in medical applications is continuously increasing, due to its excellent biodegradation performance; however, the early electrochemical characteristics and early corrosion behaviors of pure Zn remains unclear. In this study, pure Zn in simulated body fluid (SBF) was investigated via electrochemical measurement and quartz crystal microbalance (QCM) measurement. The results indicated that the corrosion resistance of pure Zn sharply decreased during the early 8 h of immersion and then gradually stabilized as the immersion time increased. According to the corrosion morphologies of Zn after different immersion times, the Zn substrate showed preferential dissolution along the grain boundary and pitting corrosion characteristic. Moreover, the corrosion products formed on the surface affected the electrochemical reaction and corrosion process of pure Zn, which significantly promoted the localized corrosion and electrochemical corrosion rate.