Double yielding mechanisms in Ti48Zr30Ni6Ta1Al1Be14 metallic glass matrix composites

Abstract

Ti-based metallic glass matrix composites (MGMCs) are composed of amorphous phase, β phase and α phase at room temperature. The stress-strain curve of the MGMCs exhibits a “double yield” phenomenon at room temperature, which disappears at low temperatures. The tensile deformation mechanism of the MGMC is deformation-induced martensitic transformation at 298 K and deformation twins at 77 K. The phase transformation starts from the dendrite boundaries, which will hinder the dislocation movement and further enhance the work hardening capability at room temperature. The stability of dendrites was evaluated by martensite trigger stress and critical α lath length, which provided guidance for exploring the deformation mechanism of amorphous composites.