Development of Ternary Magnesium Alloys for Laser Powder Bed Fusion: Optimizing Oxide Layer Thickness

Abstract

Magnesium alloys pose challenges in additive manufacturing, due to the difference between the melting temperature of magnesium oxide (2825 °C) on the powder particles and the boiling point of metallic magnesium (1093 °C). A promising approach to overcoming the difficulties is the reduction of the thickness of the high‐melting oxide layer on the surface of the particles. Magnesium alloys, each containing varying amounts of strontium, neodymium, and yttrium, are cast and subsequently analyzed in terms of their microstructures, mechanical properties, oxide layer thicknesses, and corrosion behavior. Alloying magnesium with strontium results in a reduction of the oxide layer thickness, which reaches a minimum of 0.5 wt% strontium content. The presence of rare earth elements increases the strength of the alloys, although the inclusion of neodymium results in an increase in the oxide layer thicknesses. On the other hand, the oxide layer thickness remains unaffected when alloying with yttrium. However, further increases in strontium content up to the monolithic phase Mg17Sr2 have been found to result in a reduced effect on the open‐circuit potential. Further studies should be conducted to investigate the suitability of strontium as an alloying element to reduce the oxide layer thickness of magnesium particles.