Aluminium alloys friction stir welding technology

The welding method, process technology and base principles of friction stir welding (FSW) are presented. By means of a large variety of parameter optimization of technology, the welding interface of FSW on LF6 has gotten same tensile strength with base metal. Joint strength of LY12 by FSW, non-heat-treated after welding, has reached 80% of base metal. From metallograph, it is proved that friction stir welding is a kind of solid phase joint, and with fine weld particles. There is no welding defeat such as gas hole, inclusion and crack etc. By stress tests, the residual stress of FSW is lower than general fusion welding. A series of experiments and research results have demonstrated that friction stir welding is a stable process with high repeatability, excellent joint and great potential application.