Developing novel amorphous alloys from the perspectives of entropy and shear bands

Abstract

Amorphous alloys are a new member of the amorphous material family. Due to the lack of long-range ordering of atomic arrangement, amorphous alloys show unique properties allowing for broad applications. However, their obvious weakness in the formation and deformation of amorphous alloys has not been solved in this field for a long time, which restricts their efficient development. Traditionally, the composition design of multi-component amorphous alloys mainly follows the phase diagram research paradigm to determine the composition of the low liquid phase as the foothold with a special emphasis of deep eutectics. Yet, multi-component systems without accessible phase diagrams are beyond their reach, and new theoretical breakthroughs are urgently necessitated. Starting from the thermodynamics and deformation behavior of amorphous alloys, this review proposes and demonstrates that melting entropy and vibrational entropy are the key thermodynamic parameters governing the glass formation and guiding the composition design, and the shear-band behavior can be regulated by utilizing composition adjustment, which benefit the composition conditions and requirements for obtaining amorphous alloys with high performance.[Figure not available: see fulltext.]