Browsing by Subject "Multicomponent"

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  • Levo, E.; Granberg, F.; Fridlund, C.; Nordlund, K.; Djurabekova, F. (2017)
    Single-phase multicomponent alloys of equal atomic concentrations ("equiatomic") have proven to exhibit promising mechanical and corrosion resistance properties, that are sought after in materials intended for use in hazardous environments like next-generation nuclear reactors. In this article, we investigate the damage production and dislocation mobility by simulating irradiation of elemental Ni and the alloys NiCo, NiCoCr, NiCoFe and NiFe, to assess the effect of elemental composition. We compare the defect production and the evolution of dislocation networks in the simulation cells of two different sizes, for all five studied materials. We find that the trends in defect evolution are in good agreement between the different cell sizes. The damage is generally reduced with increased alloy complexity, and the dislocation evolution is specific to each material, depending on its complexity. We show that increasing complexity of the alloys does not always lead to decreased susceptibility to damage accumulation under irradiation. We show that, for instance, the NiCo alloy behaves very similarly to Ni, while presence of Fe or Cr in the alloy even as a third component reduces the saturated level of damage substantially. Moreover, we linked the defect evolution with the dislocation transformations in the alloys. Sudden drops in defect number and large defect fluctuations from the continuous irradiation can be explained from the dislocation activity. (C) 2017 Elsevier B.V. All rights reserved.
  • Levo, Emil; Granberg, Fredric; Utt, Daniel; Albe, Karsten; Nordlund, Kai; Djurabekova, Flyura (2019)
    In search of materials with better properties, polycrystalline materials are often found to be superior to their respective single crystalline counterparts. Reduction of grain size in polycrystalline materials can drastically alter the properties of materials. When the grain sizes reach the nanometer scale, the improved mechanical response of the materials make them attractive in many applications. Multicomponent solid-solution alloys have shown to have a higher radiation tolerance compared with pure materials. Combining these advantages, we investigate the radiation tolerance of nanocrystalline multicomponent alloys. We find that these alloys withstand a much higher irradiation dose, compared with nanocrystalline Ni, before the nanocrystallinity is lost. Some of the investigated alloys managed to keep their nanocrystallinity for twice the irradiation dose as pure Ni.