Adjusting the microstructure through the deformation process is one of the ways to improve the properties of Mg alloys. Most studies have focused on the influence of the microstructure after deformation treatment on the mechanical properties of Mg alloys. In this paper, extruded and forged Mg-Gd-Y-Nd-Zr alloys were selected to investigate the corrosion performance of two deformed magnesium alloys immersed in 0.6 M NaCl solution using a hydrogen evolution test, a weight loss test, an immersion experiment, and an electrochemical test. The results showed that WE43 alloys undergoing different deformation treatments presented different microstructures, which led to different corrosion behaviors and corrosion resistance. The extruded WE43 alloy showed uniform corrosion, while the forged WE43 alloy suffered severe local galvanic corrosion. Meanwhile, the corrosion rate of the forged WE43 alloy was about four times faster than that of the extruded WE43 alloy.

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 Na₂SO₄ 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 Mg₂Ca phase acts as a microanode in microgalvanic corrosion in both NaCl and Na₂SO₄ solutions, with the Mg matrix acting as the cathode and the Al₂Ca phase acting as the microcathode to accelerate corrosion of the adjacent Mg matrix. It was also found that Cl⁻ and SO₄²⁻ have different sensibilities to microgalvanic corrosion.