Microstructure and mechanical properties of Al/Mg dissimilar laminated composites fabricated via friction stir additive manufacturing

Friction stir additive manufacturing (FSAM) is one of the most suitable processes for the manufacturing of Al/Mg dissimilar laminated composites. In this study, the single-layer single-pass FSAM and single-layer multi-pass FSAM of Al/Mg dissimilar alloys were conducted. The surface forming, macroscopic metallography, microstructure and mechanical properties were investigated. In the single-layer single-pass FSAM, the sample exhibited a peak tensile strength of 194 MPa at a rotation speed of 800 r/min and a travel speed of 75 mm/min, which was about 79.5% that of the Mg base metal. Components with good mechanical properties were obtained under low-heat-input conditions. In multi-pass FSAM, the thickness of intermetallic compounds decreased gradually from the first pass to the fourth pass. The maximum tensile strength of the alloy was obtained at 800 r/min and 75 mm/min. The tensile strength from the first pass to the fourth pass increased due to the increase of friction stir repetitions.