Features of consolidation of hybrid layered amorphous-nanocrystalline Cu / FeSiB / Cu material by severe plastic deformation

The structural mechanisms of formation of a hybrid-layered amorphous-nanocrystalline Cu / Fe75B17Si8 / Cu composite (crystalline copper as outer layers and amorphous Fe75B17Si8 alloy as inner layer) upon deformation by high-pressure torsion (HPT) were investigated. Consolidation of the constructed composite was carried out by the HPT method at a degree of deformation corresponding to 1 / 4, 1, 5, 10, 20, and 25 revolutions. It was found that the hybrid composite consists of a strengthened copper matrix with embedded hard amorphous Fe75B17Si8 phase fragments. The morphological features of the consolidation of a hybrid layered composite are associated with vortex instabilities of the deformation of material upon the HPT process. Because of the turbulence of the composite deformation, stresses arise on the irregularities of the hard phase layer, and, as a result, thin sites (bridges) appear in the layer of the amorphous Fe75B17Si8 alloy. The ductile copper layers become thinner, and the initially rectangular cross-section of the hard amorphous Fe75B17Si8 layer becomes “cigar-shaped” and bridges are formed in it. Further, with increasing degree of deformation, this layer becomes fragmented by breaking the bridges. The fragments are mixed with the matrix layer along the entire sample. The structure of the composite even after severe deformation by HPT is characterized by the absence of continuous interlayer boundaries.

1. Russian Science Foundation - 25-22-00132