Zinc (Zn) alloys have recently revolutionized and shown promising usage for degradable biomedical implants (BMI). However, due to the low strength of pure Zn, its application in the biomedical industry was limited. In the current research, an innovative biodegradable Zn-0.4Li-0.4Cu alloy produced by laser powder bed fusion (LPBF) with good mechanical properties was investigated. The Zn-0.4Li-0.4Cu alloy showed superior mechanical properties (tensile strength at 296 MPa, yield strength at 260 MPa, and after heat treatment elongation at 8.3 %), a record for biodegradable Zn alloys, as a consequence of grain refinement, second-phase precipitation of intermetallic compounds, and solid solution strengthening. The impacts of Cu and Li on the microstructures, mechanical behaviors, corrosive behavior and deterioration rate of the Zn-0.4Li-0.4Cu alloy were studied. The addition of Cu and inherent fast-cooling rate of the LPBF process are favorable for promoting the nucleation events, leading to the refinement of grains. In addition, the formation of the second-phase precipitates (CuZn and ZnLi) in the matrix was founded to further improve the mechanical properties. Moreover, the alloy showed a consistent degradation manner and a suitable degradation rate of 0.023 mm/year. Based on the findings shown above, the biodegradable Zn-0.4Li-0.4Cu alloy can be a potential candidate for vascular stents and medical applications due to its excellent mechanical properties and adequate degrading behavior.

中文翻译：

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一种新型可生物降解 Zn-0.4Li-0.4Cu 合金，具有优异的强度-延展性协同作用和激光粉末床熔融腐蚀行为


锌 (Zn) 合金最近发生了革命性的变化，并在可降解生物医学植入物 (BMI) 方面显示出广阔的应用前景。然而，由于纯锌的强度较低，其在生物医药行业的应用受到限制。在当前的研究中，研究了一种通过激光粉末床熔融（LPBF）生产的具有良好机械性能的创新型可生物降解Zn-0.4Li-0.4Cu合金。由于晶粒细化，Zn-0.4Li-0.4Cu 合金表现出优异的机械性能（拉伸强度为 296 MPa，屈服强度为 260 MPa，热处理后延伸率为 8.3%），这是可生物降解的 Zn 合金的记录，金属间化合物第二相析出，固溶强化。研究了Cu和Li对Zn-0.4Li-0.4Cu合金显微组织、力学行为、腐蚀行为和劣化速率的影响。 Cu的添加和LPBF工艺固有的快冷速率有利于促进成核事件，从而细化晶粒。此外，基体中第二相析出物（CuZn和ZnLi）的形成进一步提高了力学性能。此外，该合金表现出一致的降解方式和0.023mm/年的合适降解率。基于上述研究结果，可生物降解的 Zn-0.4Li-0.4Cu 合金由于其优异的机械性能和足够的降解行为，可能成为血管支架和医疗应用的潜在候选者。