2026/01/05
Effect of Mn on microstructural characteristics and mechanical behavior of AlSi10Mg alloys produced by laser powder bed fusion
Pourkhorshid, E.; Rometsch, P.; Bois-Brochu, A.; Taylor, A.; K.W.Marceau, R.; Grant Chen, X. (2025). Effect of Mn on microstructural characteristics and mechanical behavior of AlSi10Mg alloys produced by laser powder bed fusion. Additive Manufacturing, vol. 110, 2025, 104923.
This study investigated the effect of Mn modification on the microstructure and mechanical properties of AlSi10Mg alloys produced by laser powder bed fusion (L-PBF). The results revealed that the addition of 0.5 wt% Mn considerably improved the strength while maintaining a similar elongation level, exhibiting yield strength increases of 17 %, 30 % and 29 % in the as-manufactured (F), directly aged (T5), and solution treated plus aged (T6) conditions, respectively. In the F and T5 conditions, the Mn-modification resulted in the formation of α-Al(Mn,Fe)Si intermetallic particles inside the Si-rich network, which reinforced the network and improved the strength. After the T6 heat treatment, the Si-rich network completely disappeared in both alloys, but the formation of α-Al(Mn,Fe)Si dispersoids provided an extra strengthening contribution in the Mn-modified alloy. Most importantly, transmission electron microscopy and atom probe tomography revealed that the addition of Mn (and some extra Mg) stimulated the precipitation of a large number of Si-rich nanoparticles and MgSi-based precipitates, especially in the T5 condition. Among all the heat treatment and alloy conditions investigated, the Mn-modified alloy in the T5 condition achieved the highest strengths (yield strength: 386 MPa, ultimate tensile strength: 532 MPa). This research highlights the potential for improving the mechanical properties of AlSi10Mg alloys produced by L-PBF via a cost-effective modification of the chemical composition and provides a deeper understanding of the role of Mn in such alloys.