Investigation of Degradation Behavior and Mechanical Performance Deterioration of Magnesium Alloys in Hank's Solution

The mechanical deterioration of Mg alloys during degradation significantly impairs their service performance as biomaterial implants. In the present study, the degradation behavior of a Mg-6Zn-0.5Cu alloy was systematically examined through electrochemical measurements and immersion tests, while the mechanical integrity was assessed via tensile tests under different immersion periods. The results revealed a severe loss in mechanical properties was disproportionate to the corrosion rate. After 7 days' immersion, the ultimate tensile strength (UTS) and elongation to failure (EL) decreased by 34.4% and 60.1%, respectively, while the corrosion rate was 0.11 mm/y based on the weight loss. This severe mechanical deterioration was primarily caused by pronounced localized corrosion, which induced aggravated local stress concentration at corrosion sites, promoting microcracks initiation and leading to premature fracture of the alloy.