Study on the Effect of Microstructures and Properties of Al-Mg-Mn-Zr Alloy Welding Wire by Adding Minor Sc

Abstract The low strength of welded joints aluminum alloy welding wire materials has seriously restricted the promotion and application high-performance alloys represented by 7A52 7B52 alloy. It is urgent to develop new high-strength material meet lightweight demand 7××× series in military civilian vehicles. This paper studied effect on microstructures, mechanical properties, properties Al-6Mg-0.3Mn-0.2Zr adding minor Sc elements. result shows that it formed Al 3 Zr, Sc, (Sc 1-x , Zr x ) primary dispersive phases matrix, phase, which had triple-shell microstructure composed Zr/α(Al)/Al three-layer enclosing individually with each other from center outside. These could promote heterogeneous nucleation during solidification crystallization process welding, resulting strong refinement strengthening effects weld-zone microstructure. joint both tensile elongation increased increase contents within range 0–0.4%. was reached at Rm 365 MPa/A 5% without means heat treatment are much higher than wires used current engineering when laminated plates were prepared 0.385% Sc.