Segregation-induced ordered superstructures at general grain boundaries in a nickel-bismuth alloy

Giving grain boundaries more structure The properties of metals change depending on the composition and structure of grain boundaries in polycrystalline materials. Yu et al. discovered a surprising grain boundary superstructure in a nickel-bismuth alloy. Previously, the structure was only known to exist in a specific type of uncommon grain boundary, and experiments had focused on bicrystals. Unexpectedly, this alloy has grain boundary superstructures across a wide range of boundaries in polycrystalline samples. This likely also occurs in other alloys, which opens an avenue for grain boundary engineering to tune the physical properties of metals and ceramics. Science , this issue p. 97