复层金属界面演变与损伤行为原位可视化及动力学机制

复层金属材料性能上存在"相补效应"，可获得常规单一金属无法比拟的综合性能，在工业领域获得广泛应用。复层界面的微观形成机理与细观损伤机制是制备优质复层金属材料至为关键的理论基础。然而，一直以来归因于实时原位观察手段的缺乏，复层界面复合与损伤的微观动力学机制通常是基于大量的静态分析结果推断得到，缺乏直接的实验证据。本项目依托我国上海光源大科学装置，基于高能同步辐射硬X射线原位成像与衍射技术，以3003/4004铝合金复层板坯为典型研究对象，对液-液复合过程中的界面演变（界面的形成与失稳行为、过渡区的晶粒形核与生长、元素扩散引起的成分迁移、金属间化合物生长等），以及受载下复层界面的细观损伤行为（微裂纹的萌生、扩展与聚合等）进行实时成像与原位表征。系统研究温度梯度、冷却速率、熔体流速、力学载荷等对复层界面演变与损伤行为的调控规律与微观机理，为完善现有的和发展新型的复层金属制备技术提供理论依据。

Bimetal has the excellent properties as compared with a single alloy due to the "complementary effect", which has been widely applied in industries. The dynamics of interface forming and damaging in micsro scale is the key fundamental for preparing an excellent bimetal. However, the dynamics is usually derived from lots of static analysis due to the difficulty of in situ observation. In this proposal, we will study the interface evolution (e.g. interface forming and missing, grain nucleation and growth, solute diffusion and variation, intermetallic compound growth, etc. ); and the damage behavior (e.g. voids initiation, growth and coalescence, etc.) of 3003/4004 aluminum bimetal via in situ synchrotron radiation imaging and diffraction techniques. The influence of temperature gradient, cooling rate, flow velocity, mechanical load on the bimetal interface will be systematically studied. This project would provide a theory basic for improving the existing preparation methods of bimetal or developing the new ones.