Additively Manufactured Sustainable 8xxx-series Aluminum and an In-situ TEM Observation

Fe has been identified as a detrimental element in Al alloy systems due to its proclivity to co-precipitate with other elements. The formation of brittle intermetallic phases by Fe impedes the sustainable utilization of Al. Nevertheless, the role of Fe in laser-powder bed fusion (LPBF) processes requires reconsideration. It is noteworthy that the rapid cooling rate (on the order of 105 K/s) provided by LPBF facilitates both the freezing of doping elements and the formation of well-dispersed cellular structures and precipitates. Despite the numerous advantages offered by these sub-structures, the precise microstructure evolution during the LPBF process remains unclear. In order to gain a comprehensive understanding of the phenomenon in question, we first designed and tested several 8xxx series Al alloys with the objective of exploring the ability of these materials to resist high-temperature softening. The second part of the study involved conducting in-situ TEM heating experiments on the LPBF-built AlFeMoSiZr system.