| Summary: | As a kind of potential biomedical material, Mg–Ca alloy has attracted much attention. However, the role of Ca-containing intermetallics in microgalvanic corrosion is still controversial. In 0.6 mol/L NaCl and Na<sub>2</sub>SO<sub>4</sub> solutions, the microgalvanic corrosion behavior of the second phase and Mg matrix of Mg–Ca and Mg–Al–Ca alloys was examined. It was confirmed that the Mg<sub>2</sub>Ca phase acts as a microanode in microgalvanic corrosion in both NaCl and Na<sub>2</sub>SO<sub>4</sub> solutions, with the Mg matrix acting as the cathode and the Al<sub>2</sub>Ca phase acting as the microcathode to accelerate corrosion of the adjacent Mg matrix. It was also found that Cl<sup>−</sup> and SO<sub>4</sub><sup>2−</sup> have different sensibilities to microgalvanic corrosion.
|
|---|