Structure, mechanical characteristics, biodegradation, and in vitro cytotoxicity of magnesium alloy ZX11 processed by rotary swaging

Rotary swaging (RS) of alloy Mg–1.03Zn–0.66Ca (ZX11) was shown to refine the average grain size to 4.5 ± 1.2 µm in a longitudinal section and 4.8 ± 0.9 µm in a transverse section. In addition, a small amount of Mg₂Ca particles about 300 nm in size and Mg₆Zn₃Ca₂ particles with a size of about 100 nm was detected. This resulted in pronounced strengthening: the yield strength and the ultimate tensile strength rose to 210 ± 8 MPa and 276 ± 6 MPa, respectively, while the elongation hardly decreased (22.0 ± 1.8% and 18.3 ± 2.9% before and after RS). Furthermore, RS led to an increase in the fatigue limit of the alloy from 120 MPa to 135 MPa and did not impair its resistance to chemical corrosion. The studies in vitro showed that ZX11 induces hemolysis without inhibiting the viability of peripheral blood mononuclear cells and has a more pronounced cytotoxic effect on tumor cells in comparison with non-transformed cells. No significant difference of the latter effect between the initial and the deformed states was observed.