静止轴肩搅拌摩擦焊的研究进展

综述了静止轴肩搅拌摩擦焊的研究进展,主要涉及静止轴肩搅拌摩擦焊的基本原理以及高转速、常规转速和角焊缝的静止轴肩搅拌摩擦焊等内容.高旋转频率的静止轴肩搅拌摩擦焊在降低焊接载荷的同时,能够减小、甚至消除飞边和孔洞缺陷.常规旋转频率的静止轴肩搅拌摩擦焊可获得沿板厚方向更均匀的焊缝组织,适合于热导率差的钛合金的焊接.设计与两侧板面完全贴合的静止轴肩,以角焊缝的形式实现T形接头的焊接,拓宽了搅拌摩擦焊的应用范围.无论是高旋转频率、常规旋转频率还是角焊缝的静止轴肩搅拌摩擦焊,都存在搅拌头的磨损和过热问题,尚需开展深入、系统的研究.

Progress in the stationary shoulder friction stir welding

The progress in stationary shoulder friction stir welding(SSFSW) is reviewed in this paper,mainly involving the basic principle of SSFSW,the high rotational speed SSFSW,the SSFSW operated at conventional rotational speeds and the SSFSW for corner welds of T-joints.The high rotational speed SSFSW can reduce the process load applied on the tool,and reduce or even eliminate welding defects such as the weld flash and cavity.As for the SSFSW operated at conventional rotational speeds,the existence of the non-rotational shoulder is beneficial to obtain uniform microstructures in the thickness direction of the weld,and thus it is very suitable to weld titanium alloys characterized of a low thermal conductivity.Additionally,the SSFSW for corner welds of T-joints can also be accomplished by means of a non-rotational shoulder shaped to the internal corner of the T-type joints.Therefore,the application range of FSW is further widened.No matter be which kinds of SSFSW mentioned above,the wear and overheating of the tool system are the key problems which need to be studied in detail.