High-performance aluminum alloy with fully equiaxed grain microstructure fabricated by laser metal deposition

Since scandium has a significant refining effect on aluminum alloys, the research on aluminum-scandium alloys has continued for decades. The development of Scalmalloy which has scandium element broadens the applications for additive manufacturing (AM) for scandium–aluminum alloys. In this research, Scalmalloy is processed by the laser-melting deposition (LMD) method. A fully equiaxed grain microstructure is identified and its formation related to the characteristics of LMD-processing method is discussed. The morphology and distribution of Al₃Sc and Al₃Zr after processing is observed and discussed, and the elemental distribution is analysed. The high mechanical properties are reached and their relation to the microstructure of the Scalmalloy processed is investigated. With compiled results and observations, this study provides a better understanding of microstructure formation and the mechanical performance of Scalmalloy fabricated by the LMD method which offers a good basis for any further research in the application of LMD for high-performance aluminum alloy.