The omglysis of welding joint performance for heliarc welding of AZ31B magnesion alloy

The TIG welding process was successful used to weld AZ31B magnesium alloy in this paper.The microstructure,fratography and hardness ware investigated by optical microscope,Electron probe,XRD,SEM and hardometer respectly.The results show that the HAZ of TIG welding of AZ31B magnesium alloy was narrow;the shape of welded seam was much better and the fine isometric crystal was formed in welding seam,however,a few big grains appeared on the surface of welding.Content of aluminum in the welding metal increased which due to the evaporating of magnesium,the content of zinc is not change.Cleavages fracture was discovered in the fracture.Few pore and crack were found in cleavages fracture.