Developing a Zn alloy with high strength and uniform elongation as a biomedical device

Abstract

The equal channel angular pressing (ECAP) process was used to develop a Zn-1Mg alloy with a tensile strength of 440 MPa and uniform elongation of 11%. The uniform elongation of the ECAPed Zn-1Mg alloy is higher than that of other Zn alloys with strengths over 400 MPa. The microstructure of the ECAPed Zn-1Mg alloy evolved through dynamic recrystallization (DRX), resulting in a refined grain structure. Additionally, the lamellar eutectic structure was fragmented into sub-micrometer particles (∼0.9 μm). The high strength of the Zn-1Mg alloy is due to both grain boundary strengthening and second phase strengthening. The high uniform elongation is attributed to the presence of plate-shaped precipitates with a high density of 1014m−2. The in-vitro results indicate that ECAPed Zn-1Mg alloy has high cell viability (>100%). Meanwhile, the Zn-1Mg alloy processed by ECAP exhibited better ALP activity and alizarin red results than pure Zn. These results demonstrate that Zn-1Mg alloy is beneficial to the proliferation and differentiation of osteoblasts, and also promote blood vascular formation. The good osteogenic and angiogenic properties of the alloy are attributed to the release of Mg2+ and Zn2+ during the degradation process, which play a critical role in biochemical reactions in the human body. Therefore, the high uniform elongation and good biological properties make Zn-Mg based alloys a promising material for expanding applications in the orthopedic field.