In situ Observation of Ternary Eutectic Growth in a Directionally Solidified Mo–Si–B Alloy Using High-Energy Synchrotron X-Rays

Abstract

The present work uses synchrotron generated high‐energy X‐ray to study growth behavior at the liquid‐solid transition of multi‐component alloys during in situ directional solidification experiments at DESY, Hamburg, Germany. The unique “FlexiDS” sample environment had been used to directly investigate crystal growth of a ternary eutectic Mo‐17.5Si‐8B alloy. During the directional solidification process high energy X‐rays with a photon energy of 100 keV (λ = 0.124 Å) were used in transmission to obtain Debye‐Scherrer diffraction rings. The diffraction rings were obtained within the liquid phase, the liquid‐solid interphase and the solidified eutectic crystals by scanning through the respective observation volume of interest. The results provide strong evidences for a coupled ternary eutectic growth of the phases MoSS, Mo3Si and Mo5SiB2, which could be directly observed during in situ experiments for the first time. The results provide strong evidences for a coupled ternary eutectic growth of the phases MoSS, Mo3Si and Mo5SiB2, which could be directly observed during in situ experiments for the first time.