Solid-State Synthesis and Processing of Advanced Magnesium Alloys toward Non-traditional Functionality

针对先进镁合金和化合物的非传统功能，本项目涉及储氢、热电和生物相容性组织的研究和开发。同时，开发了固态加工成形、冷包膜和生物相容性薄膜形成技术，以制备这些新型镁合金和化合物。其中，我们开发的本体机械合金化（BMA）在非平衡相的非晶化和纳米化精细控制、多相体系中含量的精细控制以及颗粒和片状的固态加工方面得到了进一步的推广。首先，采用Mg-Ni体系作为靶体系，通过BMA进行非平衡。通过非平衡富集镍，显著改善了其加氢和脱氢特性。在二元体系基础研究的基础上，通过bbc结构寻找三元合金的材料前景广阔。本文选择Mg-Si体系来证明固态处理的有效性。在自热合成和熔融等传统工艺中，Mg_2Si的形成发生在镁的熔点以上。这导致了Mg_2Si的部分反应和合成的Mg_2Si晶粒尺寸的变细。在本方法中，Mg_2Si是在室温下以销售态合成的，晶粒尺寸被细化到与反应前的精炼硅的粒度相当。在此基础上，提出了固态回收制备增强复合镁合金零件的方法，并采用原位沉淀的Mg_2Si进行了细化和均匀化处理。此外，在Mg-Co和Mg-Fe体系中，通过非平衡过饱和，还发明了多种储氢合金，如Mg_2Co。提出了冷涂法制备Mg-Ni/Co/Fe体系储氢膜的方法。这一成功使我们能够研究和开发用于快速加氢和脱氢的新型材料薄膜体系，并深入研究通过加氢和脱氢实现金属-绝缘体过渡的功能薄膜。进一步发明了一种新的浸镀方法，在纯镁板上制备氢磷灰石涂层（Hap）作为促进硬组织恢复的生物相容性薄膜。少

Toward nontraditional functionality of advanced magnesium alloys and compounds, this project is concerning with research and development of hydrogen storage, thermoelectricity and bio-compatible tissues. At the same time, the solid-state processing and forming, the cold-coating and bio-compatible film formation are developed to produce these new magnesium alloys and compounds. Among them, our developed bulk mechanical alloying (BMA) is further promoted for fine control of non-equilibrium phase by amorphization and nano-structuring, for fine control of contents in multi-phase system and for solid-state processing from granules and platelets. At first, Mg-Ni system is employed as a target system for non-equilibration via BMA. Hydrogenation and de-hydrogenation characteristics are significantly improved by this Ni-enrichment via nonequilibration. On this fundamental study in the binary system, material search for ternary alloys becomes promising through BBC-structuring. Mg-Si system is ne … More xt selected to demonstrate the effectiveness of the solid-state processing. In the conventional processings like self-heating synthesis and melting, the formation of Mg_2Si takes place above the melting point of magnesium. This leads to partial reaction to Mg_2Si and coursing of grain size for the synthesized Mg_2Si. In the present method, Mg_2Si is sold-state synthesized at room temperature and the grain size is refined to have the equivalent particle size to that of refined silicon before reaction. On this fundamental knowledge, the solid-state recycling is proposed to fabricate the reinforced composite magnesium alloy parts and performs with in-situ precipitated Mg_2Si in fine and uniform. In addition, various hydrogen storage alloys like Mg_2Co are invented by super-saturation through non-equilibration both in Mg-Co and Mg-Fe systems. The Cold-coating is proposed to make the hydrogen storage films in Mg-Ni/Co/Fe systems even on the polymer substrates. This success enables us to make research and development of new material film systems for fast-rate hydrogenation and de-hydrogenation and to profoundly investigate the functional films with metal-insulator transition through hydrogenation and de-hydrogenation. New dipping method is further invented to yield the hydroxiapatite coating (Hap) on the pure magnesium plate as a bio-compatible film for promotion of recovery of hard tissues. Less