Microstructure And Performance Of Joints Of Aluminumalloy And Magnesium Alloy Dissimilar Materials By Friction Stir Welding

Modern automobile industry has been advocating the concept of energy-savingand environmental protection. More materials of the lightweight structure design andsuitable materials for the right parts represent the future trend of development in thecar body structure.The bimetal combination of magnesium alloy and aluminum alloycan reduce the weight of the car and ensure its strengh and stiffness.The problem ofthe connection of magnesium alloy and aluminum alloy dissimlar materials instructural design and manufacture has not been solved, restricting the bimetallicmaterials of lightweight structure design and application, being one of the key issuesthat need to be solved.This text use friction stir welding to weld magnesium alloy andaluminum alloy.In this paper,we study on the firction stir welding joints of similar anddissimilar materials of6082-T6aluminum alloy and AZ31B magnesium alloy.Firctionstir welding is good to weld these two alloys.In the joints of the similar and dissimilarmaterials,there are small equiaxed grains in stir zone,this can improve the mechanicalproperties of the joints,but there are also intermetallic compounds in the dissimilarones.some of the grains are elongated in the thermal mechanical affected zone,thegrains are coarsened in the heat affected zone.Because of the intermetalliccompounds,the microhardness of the stir zone in the dissimilar joints is much higherthan the other regions.The maximum tensile strength of6082-T6aluminum is215.5MPa, the maximum tensile strength of the AZ31B magnesium is133.5MPa, Themaximum tensile strength of the dissimilar is132.5MPa.