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

https://doi.org/10.1016/j.matlet.2024.136010

Abstract

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 β'' 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.