Comparative Study of Al-Mg-Ti(-Sc-Zr) Alloys Fabricated by Cold Metal Transfer and Electron Beam Additive Manufacturing

In this work, Al-5 Mg-0.1Ti and Al-5 Mg-0.1Ti-0.2Sc-0.1Zr (wt.%) alloys fabricated by cold metal transferCold metal transfer (CMT) and electron beam additive manufacturingElectron beam additive manufacturing (EBAM) are investigated. The Sc and Zr additionSc and Zr addition improves the processability of Al–Mg-Ti alloys by eliminating cracks in their as-deposited microstructureMicrostructure. Additionally, the Sc and Zr additionSc and Zr addition promotes columnar to equiaxed transition in the as-deposited Al–Mg-Ti alloys, exhibiting a fully equiaxed microstructureMicrostructure with grain sizes decreased by at least 70% compared to the unmodified alloys in both cases. Grain refinementGrain refinement in the as-deposited Al–Mg-Ti-Sc-Zr alloy samples is attributable to the inoculation effect of primary Al3(Sc, Zr, Ti) phase and Zener pinning effect of the solid-state precipitates of Al3ScAlSc. Moreover, the Sc and Zr additionSc and Zr addition improves the hardness of Al–Mg-Ti alloys in the as-deposited state, achieved by grain size strengtheningStrengthening and precipitate strengtheningStrengthening.