超声复合焊接研究现状及科学问题

超声复合焊接是功率超声应用的重要方向之一。由于超声独特的物理化学与力学效应，改变或改善了传统焊接工艺的效果，甚至解决了传统焊接无法克服的问题，因此，该技术在制造工业中具有潜在的应用前景。但是，目前的研究偏重超声复合焊接工艺效果，在超声能与焊接能复合机制方面的研究不够深入，对该方法能够达到的水平不清楚。综述超声复合焊接中三种主要方法--超声复合电弧焊、超声复合钎焊和超声复合搅拌摩擦焊的工艺原理、特点及成果，归纳与总结焊接工艺中超声场作用下液态金属凝固行为、固态金属流变成形行为、液态钎料合金与母材的界面行为，提出目前研究中所存在的主要科学问题及建议未来应关注的几方面内容，希望对该领域的基础研究及工程应用提供有价值的参考。

Overview on Ultrasonic-assisted Welding and Its Scientific Issues#br#

Ultrasonic-assisted welding is one of the most important applications of power ultrasound. The unique physico-chemical effects of ultrasound have been successfully used to change or improve many traditional welding processes, and to solve some insurmountable problems for conventional welding methods. Therefore, this novel technology has a wide potential application in manufacturing industries. However, the current research in this area is mainly focused on the technology results, while the understanding with regards to the interaction mechanism of the ultrasound energy and the welding energy and the level the welding method deserves, is still far from sufficient. In this paper, the characteristics and achievements of ultrasonic-assisted welding, e.g. ultrasonic-assisted arc welding, ultrasonic assisted friction stir welding and ultrasonic assisted brazing, are overviewed. Fundamental phenomena in the ultrasonic field during the welding are summarized, such as the solidification behavior of liquid alloys, rheology and deformation behavior of solid alloys, and interfacial reaction between the liquid brazing alloys and the substrate. Based on this, the main scientific issues of the current research and the suggestion on the research areas to be focused in the future are put forward. It is expected to provide a valuable reference for the fundamental research and engineering applications in this field.