Strong and ductile Al–Mn–Mg–Sc–Zr alloy achieved in fabrication-rate enhanced laser powder bed fusion

Abstract

The high cost of laser powder bed fusion (LPBF) fabricated high-strength Sc containing aluminium alloy hinders its applications. To reduce the cost, we reported a LPBF fabricated strong and ductile Al–Mn–Mg–Sc–Zr alloy using large layer thicknesses to improve the fabrication efficiency on coarse powder particles. A high relative density exceeding 99.2% was achieved at layer thicknesses up to 120 μm. In post-process heat-treated specimens, the yield strength only had a slight 6% decrease from layer thickness of 30 to 120 μm; such a decrease in strength was attributed to the larger grain size resulted from the adopted larger layer thickness. The fabricated sample at layer thickness of 120 μm still exhibited high tensile yield strength of 472 MPa and fracture strain of ∼10%. This work showed a successful application of improving the LPBF fabrication efficiency of high-strength Al–Mn–Mg–Sc–Zr alloy using large layer thickness in LPBF process.

Keywords

• al–mn–mg–sc–zr alloy
• laser powder bed fusion
• fabrication rate
• layer thickness
• high strength