Consolidation of the Amorphous Zr50Cu50 Ribbons by High‐Pressure Torsion

Abstract

High‐pressure torsion is used to consolidate the melt‐spun Cu50Zr50 amorphous ribbons. The high‐pressure torsion processing is conducted varying the strain using different numbers of anvil rotations. Optical microscopy (OM) and transmission electron microscopy (TEM), X‐ray diffraction (XRD) are used to study the effect of processing regimes on consolidation and structural changes. Oxide layers, which are present on the surface of the initial amorphous ribbons, hinder the consolidation of ribbons into fully dense samples. Individual ribbons are clearly observed in the central region of the specimen deformed for one rotation, whereas the edge regions look more consolidated due to the strain gradient along the radius during processing. An increase in strain (by increasing the number of rotations) improves the homogeneity of the consolidated samples. The high‐pressure torsion processing for ten rotations leads to the formation of dense samples with a minor concentration of small crack‐like defects in the central region. Apparently, the oxides become refined and are distributed in the matrix predominantly in the form of fine particles. Possibly, there is also some dissolution of surface oxides with the formation of a solid solution of oxygen in the amorphous metallic matrix.