Strong 3D-printed aluminium reinforced with ductile-transformable eutectic nano-skeleton

Area of Science:

• Materials Science
• Metallurgy
• Additive Manufacturing

Background:

• Lightweight metals for additive manufacturing (AM) exhibit limited strength-ductility synergy, hindering high-performance structural applications.
• Existing AM aluminum alloys struggle to balance high strength with sufficient ductility.

Purpose of the Study:

• To develop a new design strategy for additively manufactured alloys with enhanced strength-ductility synergy.
• To investigate the potential of ductile-transformable eutectic nano-skeletons (DT-ENS) for overcoming the strength-ductility trade-off.

Main Methods:

• Utilized non-equilibrium solidification to create DT-ENS in a near-eutectic Al-Er system.
• Developed an alloy family featuring a deformable Al3(Er,Mg) nano-skeleton.
• Employed laser powder bed fusion (LPBF) for alloy fabrication.

Main Results:

• Achieved AM Al-Er alloys with strengths ranging from 600-700 MPa.
• Demonstrated good printability and useful ductility in the developed alloys.
• Observed deformation twinning and strain-induced formation of 9R-type long-period stacking ordered structures within the Al3(Er,Mg) skeleton.

Conclusions:

• The DT-ENS strategy establishes a new benchmark for structural AM aluminum alloys.
• This approach provides a viable route for developing ductile intermetallics to resolve the strength-ductility compromise.
• Additive manufacturing facilitates the discovery of novel alloy systems and deformation mechanisms.