铝/钢搅拌摩擦焊金属间化合物调控研究进展

铝/钢异种金属的可靠连接是汽车行业实现轻质节能设计的重要途径. 铝和钢的热物理性能和化学性能差异大，采用固相焊方法连接较为适宜. 搅拌摩擦焊(friction stir welding, FSW)具有热输入低、高温停留时间短和焊接变形小等特点，在连接铝/钢异种金属上具有较大的优势和潜力. 铝/钢异种金属FSW高质量的核心技术之一为界面金属间化合物的调控. 基于铝/钢FSW固相连接机制，文中从焊接参数(焊接速度、焊具转速、偏移量、倾斜角和下压量)、焊具结构(搅拌针形貌、螺纹及锥角)和中间层(铝和锌等)设计等方面对界面金属间化合物调控的研究现状进行了综述，并围绕接头承载能力的提升总结了铝/钢FSW新技术(匙孔填充、自铆接及外源辅助FSW)，并进一步展望了铝/钢FSW的发展趋势.

Progress on the control of intermetallic compounds in aluminum/steel friction stir welding

The reliable joining of aluminum/steel dissimilar metals is an important way to realize lightweight and energy-saving design in the automobile industry. Solid-state welding for dissimilar aluminum/steel was more applicable due to their great differences in thermal physical and chemical properties. Friction stir welding (FSW) has great advantages and potentials in joining aluminum/steel dissimilar metals because of its low heat input, short holding time at elevated temperature and low welding distortion. One of the core technologies for high-quality aluminum/steel dissimilar FSW joints could be attributed to the control of intermetallic compounds. Based on the solid-state joining mechanism of aluminum/steel during FSW, the current progress on the regulation of interfacial intermetallic compounds was reviewed from the aspects of welding parameters (including welding speed, rotational velocity, tool offset, tilting angle and plunging depth), tool structures (pin profile, thread and taper angle) and interlayer design (Al and Zn, etc.). Based on the enhancement of joint bearing capacity, new techniques about the FSW of aluminum/steel were summarized, such as keyhole refilling, self-riveting and external assisted FSW. Furthermore, the development trends on FSW of aluminum/steel were prospected.