(1. 江苏科技大学(张家港) 冶金与材料工程学院，苏州 215600；
2. 江苏省(沙钢)钢铁研究院 板带研究室，苏州 215625；
3. 钢铁研究总院 工程用钢研究所，北京 100081)
摘 要: 采用准静态拉伸实验研究钢/铝复合板在1×10-4~1×10-2 s-1应变速率范围的拉伸力学性能与变形行为，通过扫描电镜表征分析复合界面的组织演变与失效机理。结果表明：钢/铝轧制复合界面生成厚度约8 μm、含有少量金属间化合物Fe2Al5和Fe4Al13的过渡层。复合板的强度与钢、铝层之间满足混合法则，界面具有强化作用但易产生微裂纹，界面断裂失效和基层应变硬化导致应力-应变曲线波动。高应变速率加载使界面层急剧断裂，曲线波动程度增大，但断口的界面分离程度减小。准静态拉伸过程，钢/铝界面最先萌生裂纹，层间附加应力引起界面裂纹长大并扩展至铝层内部，钢层随后颈缩导致复合板断裂失效。提高钢/铝界面的结合强度可以改善层状复合板的变形协调性和力学性能。
关键字: 钢/铝复合板；拉伸试验；复合界面；断裂；力学性能
（1. School of Metallurgy and Materials Engineering, Jiangsu University of Science and Technology (Zhangjiagang), Suzhou 215600, China;
2. Department of Plate and Strip, Jiangsu (Shagang) Institute of Research of Iron and Steel, Suzhou 215625, China;
3. Department of Structural Steels, Central Iron and Steel Research Institute, Beijing 100081, China）
Abstract:The tensile tests of steel/aluminum composite sheet were conducted at strain rate ranging from 1×10-4 s-1 to 1×10-2 s-1. It was aimed to study the deformation behavior and failure mechanism. The results show that a transition layer with thickness of about 8 μm and a few of intermetallic compounds Fe2Al5 and Fe4Al13 phases forms at the steel/aluminum roll-bonded interface. The strength of the composite sheet satisfies the mixing rule with the individual layers. The interface plays an important role in the strengthening of composite sheet. However, the bonding interface is prone to fracture due to microstructural defects. The failure of the interface and the strain hardening of the individual layer cause the stress-strain curve to fluctuate. High strain rate loading leads to the sharp break of interface layer and the obvious fluctuation of tensile curve. During the quasi-static tensile process, the cracks firstly initiate in the steel/aluminum interface, and the additional stress between the layers causes the cracks to grow and expands into aluminum layer. The steel layer subsequently necks and causes the composite sheet to fracture. By increasing the bonding strength of steel/aluminum interface, the deformation coordination and mechanical properties of the composite sheets can be improved.
Key words: steel/aluminum composite sheet; tensile test; bonding interface; fracture; mechanical properties
