Columnar to equiaxed transition in Al-Mg(-Sc)-Zr alloys produced by selective laser melting

Kun V. Yang, Yunjia Shi, Frank Palm, Xinhua Wu, Paul Rometsch

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75 Citations (Scopus)

Abstract

The addition of 1.08 wt% Sc to an Al-Mg-Zr alloy produced by selective laser melting modifies the highly coarse columnar grain structure to significantly refined columnar grains separated by sub-micron equiaxed grains at the melt pool boundaries. The latter nucleate mainly from the Al3Sc particles in the remelting zone. An almost fully equiaxed grain structure was achieved by increasing the applied volumetric energy density from 77.1 J/mm3 to 154.2 J/mm3 and the platform temperature from 35 °C to 200 °C, due to the combined effects of potent nuclei, increased remelting zone volumes and reduced thermal gradients.

Original languageEnglish
Pages (from-to)113-117
Number of pages5
JournalScripta Materialia
Volume145
DOIs
Publication statusPublished - 1 Mar 2018

Keywords

  • Aluminium‑scandium alloys
  • Columnar to equiaxed transition
  • Grain refinement
  • Selective laser melting
  • Thermal gradients

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