Correlation of microstructural evolution and tensile mechanical behavior of Gd–Al–Co–Fe series “metallic glass” fibers

Abstract

In this study, the influence of Fe doping on the microstructure and mechanical properties of Gd–Al–Co “metallic glass” fibers (MGF) was systematically investigated, and a fracture mechanics model was constructed based on the fracture morphology of MGF. Furthermore, the mechanism by which Fe doping improves the mechanical properties was revealed. The results indicate that the Gd–Al–Co–Fe series MGF has a typical amorphous structure, and with an appropriate amount of Fe increases the order degree of structure ψ, indicating that a small number of nanocluster micro-regions are formed on the amorphous matrix. With an increase in Fe doping, the tensile strength of MGF presents an initial increase and subsequent decrease. The tensile strength, Rm, of the GdAlCoFe2 MGF was the largest (up to 1199 MPa), and its fracture reliability was also superior (the threshold value of fracture was 581.93 MPa). The tensile fracture of the Gd–Al–Co–Fe series MGF is a flat fracture, showing the characteristics of brittle fracture, with vein-shaped patterns, splitting, and shear bands. A specific amount of nanocluster micro-regions formed by Fe doping effectively hindered the growth rate of crack tips during the stretching and deformation of the microfibers, and significantly improved the mechanical properties of the Gd–Al–Co–Fe series MGF. This study lays the foundation for its engineering applications in the fields of mechanics and machinery.

Keywords

• Gd–Al–Co–Fe series “metallic glass” fibers (MGF)
• Microstructure
• Tensile mechanical property
• Fracture morphology
• Fracture mechanism