A new intermetallic phase formation in Mg Si Ni magnesium-based in-situ formed alloys

Abstract The effects of nickel addition on the microstructure and phase formation in the magnesium-silicon alloy were studied. Besides the primary and eutectic in-situ formed Mg 2 Si phase in the Mg Si alloys, a new intermetallic phase was identified in the Ni-containing alloys. Based on energy-dispersive spectroscopy (EDS) and X-ray diffraction analyses, it was shown that this phase contains Mg, Ni, and Si elements, which contradicts the presence of the expected Mg 2 Ni phase. Through rigorous EDS analysis, the new in-situ formed phase was identified as (Mg,Ni) 3 Si or more accurately as Mg 8 Ni 7 Si 5 intermetallic compound, called χ-phase, which has not been reported so far in the Mg Si Ni ternary space. Finally, the properties of the studied Mg Si Ni alloys were also briefly discussed.