TY  - JOUR
AU  - Turnali, Ahmet
AU  - Hariharan, Avinash
AU  - Polatidis, Efthymios
AU  - Peter, Nicolas J.
AU  - Gehlmann, Jaqueline
AU  - Sofras, Christos
AU  - Hegedüs, Zoltan
AU  - Sayk, Lennart
AU  - Allam, Tarek
AU  - Schleifenbaum, Johannes Henrich
AU  - Haase, Christian
TI  - Harnessing additive manufacturing-induced microstructure and solute heterogeneities for the design of precipitation-strengthened alloys
JO  - Acta materialia
VL  - 298
SN  - 1359-6454
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - PUBDB-2025-03842
SP  - 121423 
PY  - 2025
AB  - Solute enrichment at lattice defects is a well-established phenomenon for promoting phase transformations. Metal additive manufacturing (AM) inherently enables this by promoting cellular structures during solidification and thermal cycling. Cellular structures exhibit compositional and lattice defect density variations between cell cores and boundaries, leading to site-specific phase-transformation (e.g., precipitation) behavior that can be selectively activated by post-AM heat treatments. Despite this potential, cellular structures have largely been treated as byproducts rather than intentionally exploited alloy design features. Guided by these insights, we designed a model Al10.5Co25Fe39.5Ni25 multi-principal element alloy to intentionally control composition and thus, precipitation driving forces across cellular structures. The alloy composition was computationally selected to promote segregation of a fast-diffusing, precipitate-forming element into the interdendritic regions during solidification in the laser powder bed fusion (PBF-LB/M) process. This segregation aligned with dislocation walls at cell boundaries, creating a “pre-conditioned” state with enhanced chemical driving force and reduced nucleation barrier for precipitation. This targeted design enabled site-specific nucleation and growth of precipitates at cell boundaries during aging. Comprehensive multiscale characterization complemented by in situ synchrotron X-ray diffraction confirmed that cellular structures accelerated precipitation, increased precipitate volume fraction and refined the precipitate size compared to the reference state where cellular structures were removed via solution annealing before aging. As a result, the alloy achieved enhanced yield strength (122.2 
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1016/j.actamat.2025.121423
UR  - https://bib-pubdb1.desy.de/record/637350
ER  -