Dong Ji-Hong, Liu Hua, Ji Shu-De, Yan De-Jun, Zhao Hua-Xia
Beijing Institute of Petrochemical Technology, Beijing 102617, China.
Beijing Academy of Safety Engineering and Technology, Beijing 102617, China.
Materials (Basel). 2022 Jan 18;15(3):696. doi: 10.3390/ma15030696.
Friction stir lap welding (FSLW) is expected to join the hybrid structure of aluminum alloy and steel. In this study, the Al-Mg-Si aluminum alloy and 301L stainless steel were diffusion bonded by FSLDW with the addition of 0.1 mm thick pure Zn interlayer, when the tool pin did not penetrate the upper aluminum sheet. The characteristics of lap interface and mechanical properties of the joint were analyzed. Under the addition of Zn interlayer, the diffusion layer structure at lap interface changed from continuous to uneven and segmented. The components of the diffusion layer were more complex, including Fe-Al intermetallic compounds (IMCs), Fe-Zn IMCs and Al-Zn eutectic. The largely changed composition and thickness of uneven and segmented diffusion layer at the lap interface played a significant role in the joint strength. The tensile shear load of Zn-added joint was 6.26 kN, increasing by 41.3% than that of Zn-not-added joint. These two joints exhibited interfacial shear fracture, while the Zn interlayer enhanced the strength of diffusion bonding by extending the propagation path of cracks.
搅拌摩擦搭接焊（FSLW）有望用于连接铝合金与钢的混合结构。在本研究中，当搅拌头销未穿透上层铝板时，通过添加0.1毫米厚的纯锌中间层，采用搅拌摩擦搭接扩散焊（FSLDW）对Al-Mg-Si铝合金和301L不锈钢进行了扩散连接。分析了搭接接头界面的特征和接头的力学性能。在添加锌中间层的情况下，搭接界面处的扩散层结构由连续变为不均匀且分段。扩散层的成分更加复杂，包括Fe-Al金属间化合物（IMC）、Fe-Zn IMC和Al-Zn共晶。搭接界面处不均匀且分段的扩散层成分和厚度的显著变化对接头强度起到了重要作用。添加锌接头的拉伸剪切载荷为6.26 kN，比未添加锌的接头提高了41.3%。这两种接头均呈现界面剪切断裂，而锌中间层通过延长裂纹扩展路径提高了扩散连接的强度。
