Microstructures and Properties of Thickness Aluminium Alloy Eleocellarium Repairing Welding Joint by Friction Stir Welding

The welding technology of 35mm thickness aluminium alloy eleocellarium repairing welding was investigated.Microstructures and properties of the welding joint have been studied by using optical microscope,scanning electron microscope,energy spectrum analysis,micro-hardness tester and electron tensile testing machine.Experimental results show that the formation of weld is good and there are no defects of tunnel,hole and groove defect by FSW after filling eleocellarium with aluminum alloy block,and there are groove defects by FSW without filling eleocellarium.The visible clear kiss defect was formed between weld nugget zone and thermal-mechanical affected zone in advencing side when welding with FSW once;The transition zone of advancing and retreating side were formed well between weld nugget zone and thermal-mechanical affected zone in advancing side when welding with FSW twice and thrice.The microhardness of once and twice welding distributing was W model and reached 56HV and 60HV in heat affected zone of advancing side.The joint tensile strength of welding once,twice and thrice reached 173,210MPa and 205MPa at rotation speed of 720r/min and welding speed of 180mm/min.