Dynamic degradation behavior of MgZn alloy in circulating m-SBF

摘要

A test platform was designed to mimic the conditions that an implanted coronary stent encounters in coronary arteries, and the degradation behavior of a biodegradable MgZn alloy in the circulating modified simulated body fluid (m-SBF) was investigated on the platform. Results indicated that the presence of circulating solution over the surface of the specimen increased its corrosion rate compared to that in static immersion test, and the diffusion of Mg~(2+) and other ions dominated the corrosion mechanism of the alloy. A corrosion layer with randomly scattering particles conglomerated to clusters on its surface was observed after 168 h of measurement. While the amount of Mg decreased from the matrix to the corrosion layer, the concentration ratio of Zn did not have a significant change. The concentrations of calcium and phosphor seemed to be gradually increased with the extension of distance from MgZn matrix to the degradation layer.