对于钛/铝异种金属熔钎焊接头，钛合金侧界面金属间化合物层的形态、厚度对接头力学性能存在显著影响.传统微观组织表征 + 宏观力学性能测试的方法无法直观获得纳米尺度下裂纹的萌生及扩展过程.基于此，采用原位TEM表征技术，对钛/铝熔钎焊接头界面金属间化合物层处的拉伸断裂行为展开研究，阐明界面金属间化合物层对接头力学性能的影响规律.结果表明，金属间化合物层物相主要以TiAl相和TiAl3相为主，在原位TEM拉伸过程中，焊缝熔合区铝合金晶粒内部容易发生位错塞积，裂纹倾向于在位错塞积处萌生扩展.界面层不是拉伸试样的薄弱区，试样倾向于在焊缝熔合区或钛合金侧发生断裂.
The shape and thickness of intermetallic layer (IMC) near the titanium alloy have a significant effect on the mechanical properties of titanium/aluminum dissimilar welding-brazing joints. The process of crack initiation and propagation at nanoscale cannot be obtained directly by the traditional method of microstructure characterization and macroscopic mechanical property test. Based on this, the tensile fracture behavior at the interface IMC of the titanium/aluminum fusion brazing joint was studied by in-situ TEM characterization technique to clarify the influence of the interface IMC on the mechanical properties of the joint. The results show that the main phases of IMC are TiAl and TiAl3. During the in-situ TEM tensile process, dislocation pile-up was easy to occur at the grain boundary in the fusion zone, and the cracks tended to initiate and propagate at this location. The interfacial layer is not the weak zone of the tensile specimen, and the specimen tends to fracture in the fusion welding zone or on the side of the titanium alloy.
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