PSI - Issue 83

Daniele Cortis et al. / Procedia Structural Integrity 83 (2026) 3–13

4

Keywords: Powder Bed Fusion - Laser Based; Al-Mg-Sc-Zr alloy; Low temperature; High temperature; Tensile properties; Portevin–Le Chatelier

Nomenclature YS

Yield Strength

UTS

Ultimate Tensile Strength

A E

Elongation

Elastic Modulus Poisson Ratio Shear Modulus

ν

G

1. Introduction Among high-strength materials tailored for Powder Bed Fusion - Laser Based (PBF-LB) technology, Aluminum (Al) alloys have gained great relevance. The addition of specific elements can significantly increase the strength via precipitation hardening, solid solution and grain refinement. One of the most successful alloys solutions are the 5xxx series alloys (i.e., Al-Mg), with Scandium (Sc) and Zirconium (Zr). During the solidification, these elements generate Al 3 (Sc,Zr) nano particles that act as nucleation sites for grain refinement and provide great thermal stability (i.e., inhibition of recrystallization) [Abrami et al. (2022)]. Also, the presence of Zr decreases the solidification range of Al reducing the tendency to form hot-cracks and simplifying PBF-LB production. Moreover, the high cooling rates (i.e., ~ 10 − 6 / 10 − 8 K/s), that occur in process like PBF-LB, determine the solubility of these elements, allowing the formation of a supersaturated solid solution [Bi et al. (2022)]. After the PBF-LB process, an aging heat treatment is recommended to control the number and the distribution of precipitates. In fact, the aging leads to the formation of coherent Al 3 (Sc,Zr) particles in the α (Al) matrix, resulting in a significantly improved strength and heat resistance. Because of high Yield Strength (YS), Ultimate Tensile Strength (UTS) and good elongation at rupture (A), these materials are comparable to high-strength 7xxx series alloys (Al- Zn) and they are ideal for high-demanding applications, like aerospace and automotive. Commercial examples of available Al-Mg-Sc-Zr materials include StrengthAl (2025) produced by Metals4Printing. Compared to the well-known SCALMALLOY ® (2021), produced by Carpenter Additive, it has a lower % of Sc and a slightly higher % of Zr (Table 1). The tensile properties are similar, with a slight advantage for SCALMALLOY ® . Data are to be considered at room temperature after aging heat treatment. In basic physics research experiments (e.g., particle detectors, accelerators, etc.), vacuum environments along with low and high temperatures are often present to reduce the influence of the outside world or to reproduce and study specific phenomena, such as astrophysics [LUNA Collaboration (2025)], dark matters [XENON Collaboration (2024)] or rare events [CUPID Collaboration (2025)]. Consequently, the development of systems and components involves the use of new high-performance materials and manufacturing techniques that can meet all design constraints [Cortis et al. (2026)]. However, these high-demanding operating conditions need a careful characterization of material properties, particularly for those produced with PBF-LB, which exhibit different behavior from those produced with traditional techniques, like casting. Thus, the aim of the paper is to investigate the mechanical behavior of the StrengthAl at different operating temperatures, including low ones that have never been examined by literature, such as -100 °C, +22 °C (i.e., room temperature), +100 °C and +200 °C. Average tensile properties, like Elastic Modulus (E), Poisson ratio ( ν ), YS, UTS and A have been determined at different temperatures, together with the stress-strain ( σ - ε ) curve. Also, the optimal PBF-LB process parameters, such as laser power (P), scanning speed (S), hatch distance (H) and layer thickness (L), will be reported. Eventually, the material microstructure and the fracture will be investigated by optical and Scanning Table 1. Chemical composition and tensile properties of StrengthAl vs SCALMALLOY ® . Material Mg (wt%) Sc (wt%) Zr (wt%) YS (MPa) 420-440 480–500 UTS (MPa) A (%) 12-17 13-16 StrengthAl 4.2-5.0 4.2-5.1 0.3-0.4 0.6-0.9 0.2-1.0 0.2-0.5 465-500 510–530 SCALMALLOY ®