Investigation into the Microstructure and Properties of 2024A1 TIG Joint with Wire Filler Subjected to Friction Stir Processing
The fusion welding methods play an important role in joining aluminum alloys,but the resulting welds suffer from a number of metallurgical issues.Therefore,it is particularly urgent to develop the effective modification/repair processes with high machining flexibility margin for aluminum alloy fusion welded joints,which is of great engineering significance for them to improve the service performance and extend the service life.A typical AA2024 aluminum alloy TIG welded joint using ER4043 wire was subjected to friction stir processing(FSP).The effect of FSP on the microstructure and properties of TIG joint was investigated.The results show that the fusion zone consists of coarse cast dendrites,Al-Si eutectic network and metallurgical defects;after FSP,the cast structure in the fusion zone is completely eliminated and transformed into a dense,uniform and fine-grained aluminum matrix composite reinforced with Si particle,resulting in a simultaneous improvement in strength-ductility synergy and corrosion resistance of TIG joint.The constitutive relationship between the microstructure evolution and property improvement of TIG joint before and after FSP is established,which reveals the microstructural origin of the performance improvement for the TIG joint after FSP,and provides new insights into the modification/repair of fusion welds of many metallic systems for enhanced performance.
Al alloysTIG jointfriction stir processingmodification and repair