%0 Journal Article %T Multi-scale microstuctural investigation of a new Al-Mn-Ni-Cu-Zr aluminium alloy processed by laser powder bed fusion %+ Science et Ingénierie des Matériaux et Procédés (SIMaP) %+ Constellium Technology Center (C-TEC) %A Buttard, Maxence %A Chehab, Béchir %A Shahani, Ravi %A Robaut, Florence %A Renou, Gilles %A Tassin, Catherine %A Deschamps, Alexis %A Rauch, Edgar %A Donnadieu, Patricia %A Blandin, Jean-Jacques %A Martin, Guilhem %< avec comité de lecture %@ 2589-1529 %J Materialia %I Elsevier %V 18 %P 101160 %8 2021 %D 2021 %R 10.1016/j.mtla.2021.101160 %K Laser powder bed fusion (L-PBF) %K Al-alloys %K Microstructure %K Additive Manufacturing %K TEM %Z Engineering Sciences [physics]/MaterialsJournal articles %X Traditional high strength aluminum alloys such as the 2xxx or 7xxx series are prone to cracking when processed by additive manufacturing. Designing new aluminum alloys that can be processed crack-free by Laser Powder Bed Fusion (L-PBF) while exhibiting comparable or enhanced mechanical properties is a major target, which may be reached by including in the alloy design strategy specific features of this processing route such as the very high cooling rates. Here, we study a novel Al-4Mn-3Ni-2Cu-2Zr alloy processed by L-PBF, which shows some specific features in comparison to other Al-alloys developed for additive manufacturing. We establish the relationships between the processing conditions and the specific features of the microstructure inherited from L-PBF based on a multi-scale microstructural characterization approach from the melt pool scale up to the nanoscale using X-ray diffraction and electron microscopy with a special focus on Automated Crystal Orientation Mapping (ACOM) in transmission. At the melt pool scale, three regions have been identified: FEZ (Fine Equiaxed Zone), CZ (Columnar Zone) and CEZ (Coarse Equiaxed Zone) giving a hierarchical architecture to the microstructure. Each region has been thoroughly characterized by coupling ACOM and chemical mapping. Five different intermetallic phases have been identified in the as-built microstructure: Al3Zr, Al3Ni2, Al9Ni2, Al60 Mn 11Ni 14, and Al2Cu. The spatial distribution of these intermetallic phases has been found to vary within a given molten pool. The solidification sequence and the various mechanisms involved in the formation of this peculiar microstructure are discussed in the light of our multi-scale microstructural observations along with solidification thermodynamic calculations. %G English %2 https://cnrs.hal.science/hal-03370486/document %2 https://cnrs.hal.science/hal-03370486/file/Article%20multiscale%20etc.pdf %L hal-03370486 %U https://cnrs.hal.science/hal-03370486 %~ UGA %~ CNRS %~ INPG %~ SIMAP %~ INC-CNRS %~ TEST-HALCNRS %~ UGA-EPE %~ TEST2-HALCNRS