铝合金搅拌摩擦焊接头缺陷及焊件结构问题控制策略的研究进展

搅拌摩擦焊(Friction Stir Welding，FSW)是近些年发展起来的一种固态连接工艺，尤其适用于铝合金材料的焊接。概述了搅拌摩擦焊的局限性，主要包括接头处存在钥匙孔、焊缝减薄等缺陷及复杂结构铝合金难以焊接等问题。研究表明，通过工艺方法、流程及参量的优化能够对焊接接头缺陷和焊件结构问题进行有效控制。由此，归纳了铝合金搅拌摩擦焊接头存在的关键问题及解决策略，分析了每种工艺方法的适用对象及条件，包括摩擦塞焊(Friction Plug Welding，FPW)、填充式搅拌摩擦焊(Filled Friction Stir Welding，FFSW)、回抽式FSW、静止轴肩搅拌摩擦焊(Stationary Shoulder Friction Stir Welded，SSFSW)、沉积式FSW、双轴肩搅拌摩擦焊(Bobbin Tool Friction Stir Welding，BT-FSW)和无倾角FSW。详细探讨了每种工艺的原理和机制，阐述了每种工艺的优缺点，重点介绍了工艺的参数优化调控、辅助设备的添加及工序的改进对修复接头组织与力学性能的影响。对铝合金搅拌摩擦焊的回顾总结，将为获得高质量搅拌摩擦焊接头，实现复杂结构件焊接提供参考依据。在此基础上，对铝合金搅拌摩擦焊现存问题及挑战的解决进行了展望。

#$NP Research Progress of Defect Control Strategy for Al Alloy Stir Friction Welding Head and Welding Structure

Compared with steels, Al alloys possess lots of advantages, such as light specific gravity, good plasticity, excellent thermal conductivity, corrosion resistant, etc. Nowadays, more and more products are designed by welding structure of Al alloys and used in the shipbuilding, automobile manufacturing, aerospace and petrochemical industry, presenting unique advantages and significant economic benefits. The welding problems of Al alloys have always been a focus of attention, such as cracks, pores, overburning, etc. As a result, the safety problems severely restrict the industrial application of Al alloys. Friction stir welding (FSW) is a solid-state bonding process. FSW achieves the joining between materials through the generation of frictional heat and strong plastic deformation. At the same time, the stirring head shoulder applies a certain compressive stress to the material to ensure a high-density and defect-free weld. Compared with the traditional fusion welding process, it has the advantages of good joint quality, refined microstructure, excellent fatigue performance, low peak temperature, energy saving, etc. Therefore, FSW is exactly suitable for the welding of Al alloys.