J. Mater. Sci. Technol. ›› 2021, Vol. 81: 97-107.DOI: 10.1016/j.jmst.2021.01.007

• Research Article • Previous Articles     Next Articles

Effect of glycine addition on the in-vitro corrosion behavior of AZ31 magnesium alloy in Hank’s solution

Durga Bhakta Pokharela,b, Liping Wuc, Junhua Donga,b,*(), Amar Prasad Yadava,d, Dhruba Babu Subedia,b, Madhusudan Dhakala,b, Lin Zhac, Xin Mua, Aniefiok Joseph Umoha,b, Wei Kec   

  1. aShenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
    bSchool of Material Science and Engineering, University of Science and Technology of China, Hefei, 230026, China
    cEnvironmental Corrosion Center, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
    dCentral Department of Chemistry, Tribhuvan University, Kirtipur, Nepal
  • Received:2020-06-17 Revised:2020-09-06 Accepted:2020-10-21 Published:2021-01-05 Online:2021-01-05
  • Contact: Junhua Dong
  • About author:*Shenyang National Laboratory for Materials Science(SYNL), Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016,China.E-mail address: jhdong@imr.ac.cn (J. Dong).

Abstract:

This study reports on the effect of the addition of Glycine to Hank’s solution on the in-vitro corrosion behavior of AZ31 magnesium (Mg) alloy at 37 ℃ and a pH of 7.4 studied by using potentiodynamic polarization (PDP), hydrogen collecting techniques and electrochemical impedance spectroscopy (EIS) in combination with surface characterization techniques such as optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy analysis (XPS). The results reveal that adsorption of glycine initially subdues the dissolution of AZ31 Mg alloy while in long run it enhances the dissolution of the alloy due to the commencement of the chelation effect of glycine with Ca2+ released from hydroxyapatite. The chelation of glycine with Ca2+ induces the formation of cracks in the surface film which further promotes the dissolution of AZ31 Mg alloy thereby forming a porous corrosion products layer on the surface of the alloy. As a result, both the continuous dissolution of AZ31 magnesium alloy and the hydrogen evolution rate (HER) are enhanced with increasing the immersion time in Hank’s solution.

Key words: AZ31 Mg alloy, Glycine, Hank’s solution, EIS, Chelating effect