激光选区熔化制备锌基金属可降解医用植入体的工艺及性能研究

Zn is an essential element in human body. Degradation of Zn is slower than that of Mg and faster than Fe, which is attracting attention as a new biodegradable metal. Selective laser melting (SLM) has unique advantages for manufacturing personalized medical implants with complicated geometry. However, Zn is easy to produce large amounts of metal vapor under the action of laser, resulting in process instability and porosity. SLM processing of Zn faces great challenges, and the current research is very limited. In our previous research, typical implant structures with density over 99.90% were obtained in a reasonable processing window using pure Zn powder, which showed the feasibility of SLM for manufacturing Zinc based metal implants. Although the mechanical properties of pure Zn SLM parts were better than or equivalent to those obtained by most manufacturing methods, they still cannot satisfy the requirements of medical implants. Alloying is the critical issues for practical applications. In this project, Zn alloy medical implants are manufactured by SLM. The effect of metal evaporation and laser energy input on formation quality and micro structure is investigated. The mechanical properties are improved by the optimization of alloying elements and processing parameters. The strengthening technology and mechanism are clarified. The effect of alloying elements, structure geometry and surface quality on bio compatibility and biodegradability is studied. The good bio performance of SLM parts are achieved. The results are expected to provide theoretical basis and experimental data for the application of additive manufacturing of Zn based metals for biodegradable implants.

锌是人体必需元素，降解速度介于镁和铁之间，是一种新型可降解医用金属。激光选区熔化（SLM）在个性化医用植入体制备上具有独特优势，成功用于多种医用金属的增材制造。锌的沸点低，激光熔化时产生大量金属蒸气，导致质量恶化和合金烧损。目前锌金属SLM研究很少，尚无复杂结构成形件及力学和生物性能报道。前期采用纯锌粉末首次制备了锌金属多孔结构和血管支架结构，成形质量良好，初步证明了SLM制造锌金属复杂结构的可行性。纯锌的力学性能尚无法满足植入体要求，本课题采用SLM制备锌合金可降解医用植入体。通过工艺优化获得典型医用植入体结构，研究金属蒸发和激光能量对成形质量和微观组织的作用机理，揭示工艺参数和合金化对力学性能的影响规律及调控机制，提升锌基金属SLM成形件的力学性能，阐明材料成分、几何结构和表面质量对生物相容性和生物降解行为的影响规律，为锌基金属可降解医用植入体的增材制造提供理论依据和应用基础。

锌是人体必需元素，降解速度介于镁和铁之间，是一种新型可降解医用金属。激光选区熔化（SLM）在个性化医用植入体制备上具有独特优势，成功用于多种医用金属的增材制造。锌的沸点低，激光熔化时产生大量金属蒸气，导致质量恶化和合金烧损。目前锌金属SLM研究很少，尚无复杂结构成形件及力学和生物性能报道。前期采用纯锌粉末首次制备了锌金属多孔结构和血管支架结构，成形质量良好，初步证明了SLM制造锌金属复杂结构的可行性。纯锌的力学性能尚无法满足植入体要求，本课题采用SLM制备锌合金可降解医用植入体。通过工艺优化获得典型医用植入体结构，研究金属蒸发和激光能量对成形质量和微观组织的作用机理，揭示工艺参数和合金化对力学性能的影响规律及调控机制，提升锌基金属SLM成形件的力学性能，阐明材料成分、几何结构和表面质量对生物相容性和生物降解行为的影响规律，为锌基金属可降解医用植入体的增材制造提供理论依据和应用基础。