A novel high-strength Al-La-Mg-Mn alloy for selective laser melting

Developing high-strength Al-(La, Ce) alloys for additive manufacturing (AM) would entail considerable economic benefits. In this work, a novel near-eutectic Al-La alloy containing 5.50 wt.% Mg and 0.60 wt.% Mn was designed and fabricated via selective laser melting (SLM). Submicron Al11La3 intermetallics with 3D continuous cellular-dendritic and granular morphologies were observed at the interior and boundary of the melt pool, respectively. Interestingly, these intermetallics are hierarchical and contained numerous Al6Mn and Mg2Si secondary nanoprecipitates. The as-fabricated alloy exhibited a tensile yield strength (YS) of 334 MPa and ultimate tensile strength (UTS) of 588 MPa at room temperature, which is the high-est UTS reported for Al-(La, Ce) alloys with an appreciable failure strain of similar to 6.4%. The 3D continuous cellular dendritic intermetallic and high Mg content afford significant strengthening and work harden-ing ability. In addition, the hierarchical feature of the intermetallics generated additional microcracks to coordinate the deformation.(c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.