As Mg-based alloys are lightweight alloys designed for the transportation industry. It is important to understand the behavior of magnesium under dynamic loading in a humid environment. Pure magnesium was synthesized by disintegrated melt deposition at 750°C. The XRD diffraction pattern revealed that the dominant orientations were (0002) and \(\left(10\overline{1}1\right)\) . The electrochemical tests performed using a droplet cell showed that the corrosion potential was ca. − 1.5 V versus Ag/AgCl/KCl(sat.). A cavitation-erosion test performed with a cavitating jet device showed that the main mechanism of damage was twinning and ductile fracture. Initially, deformation twins formed in grains with an orientation conducive to twinning and in direct contact with the cavitation pulse impact sites. As the test duration increased, the number of grains with deformation twins increased. Moreover, double twins, twin-twin interactions, and twin-wall intersections were formed. Twinning also caused grain fragmentation, leading to dimple formation typical for a plastic mode of fracture. In contrast, brittle fracture with lamellar facets was also revealed. After the test, the surface hardness increased 89% compared to the initial hardness due to twinning and MgO layer formation, which contributed to a reduction in erosion rates. MgO also contributed to crack closure.
