On the solidification characteristics, deformation, and functionally graded interfaces in additively manufactured hybrid aluminum alloys

AlSi10Mg powder is deposited on top of a cast AA2618 substrate via laser powder bed fusion technique to form hybrid aluminum parts for additive repair purposes. The characterization of the additively manufactured (AM) hybrid aluminum alloys is conducted through advanced electron microscopy techniques across the interface, mechanical testing, validation of elasticity models, and crystallographic orientations analysis. In addition, the fracture behavior of the hybrid samples is investigated through electron microscopy analysis and the results are compared with those of AlSi10Mg and cast AA2618. The microstructural and physical properties of the hybrid bi-material are also discussed based on the solidification and diffusion phenomena. Finally, the dependency of elastic and shear moduli on the distance from the interface and solute concentration are separately evaluated via elastic-field mathematical equations. It is observed that an integrated bond is formed at the interface of the two dissimilar alloys showing suitable mechanical properties and shear strength, as well as a modified microstructure compared to the substrate material. The outcome of this work can be employed as a first step to use hybrid aluminum alloys in the blow molding industry and for repair and maintenance purposes. [Display omitted] •Fabricate a functionally graded AA2618/AlSi10Mg hybrid material with an integrated interface.•Present an efficient method to overcome hot tear induced failure in Al-Cu-Fe-Mg alloying system.•Interpret hot tear formation and blunting mechanisms in AA2618 substrate regarding residual stress.•Mathematical equations on dependency of elastic and shear moduli on distance and concentration.•Describe an increase in strain hardening of hybrid material via representative Peierls-Nabarro stress.