The Effect of Mn Content on the Mechanical and Degradation Properties of Porous Zn–Li Alloy Scaffolds

To solve the challenges of pure Zn scaffolds, including poor mechanical properties, slow corrosion rates, and limited biocompatibility, porous Zn–0.8Li–xMn (x = 0.1, 0.4 and 0.8) scaffolds with a porosity of 70% are fabricated using an infiltration casting technique. The prepared scaffold microstructure, mechanical properties, corrosion rate, and cytotoxicity are investigated. The results show that the addition of 0.1 wt% Mn to Zn–0.8Li significantly improves the mechanical properties, achieving a yield strength of 28.4 ± 0.70 MPa and an elastic modulus of 1.74 ± 0.17 GPa. The addition of Mn accelerates the degradation rate, with the Zn–0.8Li–0.8Mn scaffold achieving a rate of 0.31 mm/year by the fourth week, close to the ideal degradation rate for biodegradable implants. Cell experiments show that the addition of elemental Mn promotes the osteoblastic activity of the scaffolds. The study found that when Mn content exceeded 0.4 wt%, the Zn/β‐LiZn₄ lamellar structure weakened, slightly reducing mechanical strength. However, the precipitation of the MnZn₁₃ phase induces galvanic corrosion, accelerating the scaffold's degradation rate. Overall, Zn–0.8Li–0.8Mn scaffolds excel by accelerating degradation while retaining strong mechanical properties. Thus, the addition of moderate amounts of Mn improves the mechanical and degradation properties of Zn–Li scaffolds, which has great potential for orthopedic clinical applications.