Improving Mechanical Properties, Corrosion Resistance and Biocompatibility of Zn-1Mg-0.3Y Alloys Through Equal Channel Angular Pressing

Abstract

This paper discusses refining the microstructure of Zn–Mg–Y alloy via equal channel angular pressing (ECAP), leading to enhanced mechanical properties of the Zn alloy. Following ECAP, the strength and elongation of the Zn–Mg–Y alloy increased from 227 MPa and 3% in the as-cast state to 350 MPa and 23%. The increase in strength is primarily attributed to the reduction in grain size, the refinement of the lamellar eutectic Mg2Zn11 phase, and the granular YZn12 phase. Additionally, the nanoscale precipitates generated during ECAP-induced deformation can also contribute positively to strengthening. Beyond strength enhancement, the refinement of the second phase can mitigate stress concentration at the Zn/Mg2Zn11 and Zn/YZn12 interfaces, thereby enhancing the deformability of the Zn alloy. Electrochemical and immersion experiments demonstrate an enhanced corrosion resistance of the Zn–Mg–Y alloy after ECAP processing. This improvement can be primarily attributed to the increased uniformity of the microstructure after refinement, which inhibits the occurrence of localized corrosion. Regarding biocompatibility, Zn–Mg–Y alloys in both the cast and ECAP states exhibited cell viabilities exceeding 100% in MC3T3 cell cultures using 50% and 25% extracts, outperforming the control group of Ti. In summary, the Zn–Mg–Y alloy prepared through ECAP significantly enhances mechanical properties, corrosion resistance, and biocompatibility. These findings open new avenues for advancing the development of improved degradable Zn alloys.