Microstructure and properties of a novel high-performance Al-Si-Mg alloy fabricated by wire-arc directed energy deposition

In this study, a novel high-performance Al -Si -Mg alloy was fabricated using wire-arc directed energy deposition (wire-arc DED), resulting in remarkable mechanical properties, including a yield strength of 299.2 +/- 1.3 MPa, an ultimate tensile strength of 376.5 +/- 8.1 MPa and an elongation an elongation of 6.9 +/- 0.3 %. The heat-treated samples exhibited a uniform distribution of a significant quantity of nanoscale l3" phases, serving as the primary strengthening phase and contributing to substantial precipitation strengthening. The addition of Mn facilitates the formation of Al6(Mn, Fe) phase, effectively suppressed the formation of detrimental Fe-rich phases. However, the presence of numerous pores and the lack of fusion regions emerged as significant factors impacting mechanical properties.