Can Severe Plastic Deformation Tune Nanocrystallization in Fe-Based Metallic Glasses?

The effects of severe plastic deformation (SPD) by means of high-pressure torsion (HPT) on the structural properties of the two iron-based metallic glasses FeCuNbSiB and FeCoSiBPCu have been investigated and compared. While for FeCuNbSiB, HPT processing allows us to extend the known consolidation and deformation ranges, HPT processing of FeCoSiBPCu for the first time ever achieves consolidation and deformation with a minimum number of cracks. Using numerous analyses such as X-ray diffraction, dynamic mechanical analyses, and differential scanning calorimetry, as well as optical and transmission electron microscopy, clearly reveals that FeCoSiBPCu exhibits HPT-induced crystallization phenomena, while FeCuNbSiB does not crystallize even at the highest HPT-deformation degrees applied.