Structure and mechanical properties of hot-extruded Mg-Y-Zn-Mn biodegradable alloys

Magnesium-based implants are considered to be a promising class of materials for clinical applications because of their combination of biodegradability and mechanical properties that match well those of the human bone. Their resorbability eliminates the need for secondary surgery for implant removal. Among magnesium-based alloys, Mg-Y-Zn-Mn alloys are excellent candidates for biomedical applications due to their high mechanical properties and corrosion resistance. This study examines the impact of yttrium (Y) and zinc (Zn) content, as well as the extrusion temperature, on the structure and mechanical properties of Mg-Y-Zn-Mn alloys with a Y/Zn atomic ratio of 1.5. The alloys display varying mechanical properties in the directions parallel and perpendicular to the extrusion direction, owing to a bimodal microstructure featuring large non-recrystallized grains and fiber texture. It was discovered that enhancing the summary content of Y and Zn from 1.8 to 5.1 wt% led to an improvement in strength without a significant reduction in ductility. This was due to the bimodal microstructure, precipitation strengthening and solid-solution hardening effect, as well as the structural accommodation. The alloy of Mg-3.4 wt% Y-1.7 wt% Zn-0.8 wt% Mn (Mg-1.0 at% Y-0.6 at% Zn-0.4 at%) extruded at 450 degrees C degrees C demonstrated the ultimate tensile strength of 348 MPa, yield strength of 261 MPa, and elongation at fracture of 10.7 %.