航天用高强韧铝合金增材制造形性协同调控机理研究

铝合金增材制造技术能满足航天领域个性化复杂轴系零件的制造，然而较难完全突破形状精度与力学强韧性协同调控的技术挑战，亟需开发可稳定增材制造用新型高强韧铝合金材料。本项目以卫星激光用铝合金轴承指向机构零件需求为牵引，设计和优化增材制造用新型高强韧Al-Mg2Si合金，建立合金成分、打印策略与SLM成形性的关联基础，揭示SLM极端冶金条件下合金的凝固行为与组织演化规律，探明SLM成形性与强韧化的协同调控机理；重点研究原位纳米Mg2Si共晶生长规律以及时效析出亚稳强化相脱溶析出规律，明晰亚稳强化相成分、结构和界面的关系以及对力学性能的影响，确立“合金设计-SLM制造-组织演化-成形性/强韧化协同调控”之间的一体化关联理论，进而为增材制造高强韧铝合金开发与研究提供新思路，最终满足某些关键领域对个性化、高性能铝合金构件制造的需求。

Additive manufactured aluminum alloy can meet the requirement of the manufacturing of personalized complex shafting parts in the aerospace field. However, it is difficult to break through the technical challenges of coordinated control of shape accuracy and high strength and ductility. It is urgent to develop a new high-strength and high-ductile aluminum alloy for stable additive manufacturing (AM). In present project, a new type of high strength and toughness Al-Mg2Si alloy for additive manufacturing is designed and optimized based on the demand of aluminum alloy bearing pointing mechanism parts of satellite laser. The correlation basis of the composition of alloy, strategy and SLM formability is established. The solidification behavior and microstructure evolution of SLMed Al-Mg2Si alloy under extreme metallurgical conditions are revealed, and the synergistic regulation mechanism of SLM formability and strengthening is explored The growth of in-situ nano-Mg2Si eutectic and the de-solvation and precipitation of precipitated metastable strengthening phase are clarified; and the relationship between the composition, microstructure and interface of metastable strengthening phase and the effect on mechanical properties are clarified, and the integrated correlation of "alloy design-SLM process- microstructure- shaping and mechanical properties coordination" is established, which provides a new idea for the development and research of high-strength and high-ductile AMed aluminum alloy to meet the requirements of some key areas for personalized and high-performance aluminum alloy component manufacturing.