Investigations into stress corrosion cracking behaviour of AZ91D magnesium alloy in physiological environment

摘要

Mechanical integrity of biodegradable magnesium alloys implant remains an issue in bio-chemical and corrosive environment of human body because of their unacceptably high degradation rate. Therefore, understanding of simultaneous effect of stress and corrosive environment, i.e., stress corrosion cracking (SCC) of these alloys in physiological environment is essential before their actual use. To establish the SCC susceptibility, slow strain rate testing (SSRT) was carried out on the tensile specimens of a magnesium alloy, AZ91D in modified simulated body fluid (m-SBF) and air at different strain rates. Fracture surfaces of tested specimens were analysed using scanning electron microscopy (SEM) in order to examine the features of SCC. The alloy was found to be susceptible to SCC.