Skip to Main content Skip to Navigation
Journal articles

Multi-scale microstuctural investigation of a new Al-Mn-Ni-Cu-Zr aluminium alloy processed by laser powder bed fusion

Abstract : 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.
Document type :
Journal articles
Complete list of metadata

https://hal-cnrs.archives-ouvertes.fr/hal-03370486
Contributor : Patricia Donnadieu Connect in order to contact the contributor
Submitted on : Monday, October 18, 2021 - 10:23:15 AM
Last modification on : Thursday, October 21, 2021 - 5:09:39 AM

File

Article multiscale etc.pdf
Files produced by the author(s)

Identifiers

Collections

Citation

Maxence Buttard, Béchir Chehab, Ravi Shahani, Florence Robaut, Gilles Renou, et al.. Multi-scale microstuctural investigation of a new Al-Mn-Ni-Cu-Zr aluminium alloy processed by laser powder bed fusion. Materialia, Elsevier, 2021, 18, pp.101160. ⟨10.1016/j.mtla.2021.101160⟩. ⟨hal-03370486⟩

Share

Metrics

Record views

6