铝/钛异种金属轻量化结构在航空、航天、汽车等领域存在迫切需求，针对铝/钛异种金属可焊性差、界面反应复杂、金属间化合物难控制等问题，本项目基于强变形致快扩散行为，探索铝/钛异种金属搅拌摩擦扩散焊搭接新方法。从产热和变形协同作用角度，提出搅拌摩擦扩散焊搭接焊具设计准则，探讨焊接工艺对接头宏观成形和界面微观结构的影响。揭示强变形致界面元素快扩散机理，阐明界面金属间化合物的形成机制和演化规律，分析强变形作用下界面区域富钛夹层结构和机械合金化非晶层的成因和条件。阐明界面宏微观一体化调控原理，建立界面微区力学行为和接头宏观承载特性的关联，实现界面结构和接头性能的协同调控,获得性能优良的铝/钛异种金属接头。本方法的提出将为铝/钛异种金属的优质连接及其轻量化结构的应用提供新的解决方案，对其他基于以界面材料变形和扩散为基础的异种金属固相连接机制的揭示也具有较大的参考价值。

There is stringent requirement for lightweight structures of Al/Ti dissimilar metals in various industrial fields such as aeronautics, astronautics and automobile. Due to the challenge in poor weldability, complex interfacial reaction and controlling of intermetallic compounds (IMCs) for Al/Ti dissimilar metals joining, the new method of friction stir diffusion lap welding (FSDLW) based on severe deformation induced fast diffusion behavior was investigated in the present study. The design rules of tools for FSDLW were proposed from the aspects of heat generation and deformation synergy. The joint formation and interface microstructure were obtained based on the welding process development. The fast diffusion mechanism induced by severe deformation was revealed. The formation mechanism and evolution of interfacial IMCs were discussed. The formation of Ti-rich sandwich structure and amorphous layer at the interface under severe deformation were analyzed. The interface macro-micro integrate controlling theory was clarified. The relationship between interfacial micro-mechanical behavior and macro-bearing characteristics of joint was established. The cooperative control of interface microstructure and bearing characteristics of joint was achieved. High quality joints of Al/Ti dissimilar metals were obtained. The method proposed will provide new solution for high quality joining and applications of lightweight structures of Al/Ti dissimilar metals, which is also important reference for investigation the mechanism of solid state bonding based on deformation and diffusion of interfacial materials.