Effect of the test regimes on the corrosion resistance of the Zn-1Fe-1Mg alloy

Abstract

Bioresorbable zinc alloys are ever more often regarded as promising materials for medical implants and vascular stents since they have a lower corrosion rate in a physiological environment in comparison with magnesium alloys. At the same time, products made of zinc alloys must have a controlled corrosion rate to provide the required time for the recovery of the body. It is known that in determining the corrosion rate, an important role is played by the choice of the test method and its parameters (corrosive environment, environment temperature, the sample's exposure time in the corrosive environment). In the present study, the gravimetric method was used, based on a precise measurement of the substance mass prior to and after testing. The surface of the samples subjected to corrosion tests was investigated using scanning electron microscopy and energy-dispersive analysis. The aim of the present study is to reveal the effect of the samples' exposure time in a corrosive environment, as well as the frequency of surface cleaning, on the corrosion resistance of the Zn-1Fe-1Mg biodegradable zinc alloy. It is shown that under the same test conditions but different frequencies of surface cleaning, the corrosion rates may differ by a factor of 3.8.