Anelastic Relaxations to Identify Structural Rearrangement and Phase Transitions in Amorphous Metallic Composites with Shape Memory Effect

Abstract

In recent decades, metallic glasses have attracted great scientific and technological interest because of their unique properties, such as the lack of long-range atomic regularity and their compositional homogeneity. These amorphous alloys have better mechanical properties, resistance to the corrosion and high fracture resistance when compared to their crystalline counterpart. However, a comprehensive physical understanding of the disordered structure, its structural evolution and how it affects the mechanical properties of metallic glasses is considered one of the major challenges in Condensed Matter Physics and Materials Science. In this aspect, Mechanical Spectroscopy, which provides the anelastic spectra (internal friction and elastic modulus) as a function of temperature is considered a very sensitive technique to identify phase transitions and dynamic processes by which relevant information are obtained for the understanding of the structural and vibrational changes in metallic glasses. The technique allows to study the mechanisms involved in the formation of nanostructures, such as supercluster and molecular-like structures, as well as to understand how they favor the growth of nanocrystals within the amorphous matrix through analysis of the anelastic spectra of bulk and ribbons metallic glasses and their composites. Different methods will allow to investigate the mechanisms that occur in the metallic glasses and the effect that the formation and growth of nanostructures cause at the amorphous/crystal interface into the metallic glasses composites with shape memory. Data collected by Mechanical Spectroscopy together with other techniques will enable the investigation of the structural evolution due to dynamic processes related to elastic contributions and phase transitions that occur in metallic glasses and their composites. This may provide a better understanding of the mechanical properties and deformation mechanisms occurring in metallic glasses and their composites. In addition, this research project aims to training new researchers.