Friction stir welding between the high-pressure die casting of AZ91 magnesium alloy and A383 aluminum alloy

Defect-free Friction stir welded joints between the AZ91 Mg alloy and A383 Al alloy were obtained at a welding speed of 40 mm/min and a rotational speed of 900 rpm. Mg and Al were intermixed and presented intercalated strips microstructure. The second phases Si, Al3Mg2, Al12Mg17 and Mg2Si distributed uniformly in stir zone at a rotational speed of 900 rpm, and there is a narrow intermetallic compounds layer (∼10 μm) at the interface of the two base metals. The tensile strength of the dissimilar AZ91/A383 joint is 93 MPa, which is approximately 45% of the A383 alloy. The sufficient material intermixing and uniform distribution of second phases are helpful to the joint properties.