Formation of thin amorphous shear bands has been recently shown to enable plastic flow in crystalline SmCo₅ in the absence of dislocations. To bring insights into the criteria for when this mechanism can be active, here we analyze energetics and atomic structure of deformation-induced shear bands in SmCo₅. We find that the formation energy of amorphous shear bands is significantly lower than cleavage energies on different crystallographic planes. The density of the atoms in the shear bands decreases by less than 2% due to the amorphization, which indicates a very small dilation. Analysis of local ordering shows that the amorphous shear bands are more disordered than a melt-quenched sample and the overall fraction of icosahedra is much lower than usually reported in metallic glasses, such as Cu–Zr. The influence of amorphous shear bands on the evolution of grain orientations is also discussed.

最近已显示出形成无定形的剪切带，可以在没有位错的情况下使塑料在SmCo ₅晶体中流动。为了深入了解何时可以激活该机制，我们在这里分析了SmCo ₅中形变剪切带的能量和原子结构。。我们发现，非晶剪切带的形成能明显低于不同晶体平面上的分裂能。剪切带中原子的密度由于非晶化而降低了不到2％，这表明膨胀很小。局部有序分析表明，非晶态剪切带比熔融淬火样品更无序，二十面体的总含量远低于金属玻璃（如Cu-Zr）中通常报道的水平。还讨论了非晶态剪切带对晶粒取向演化的影响。