Materials & Design (Dec 2018)
Compressive mechanical properties and failure modes of Zr-based bulk metallic glass composites containing tungsten springs
Abstract
A novel kind of Zr-based bulk metallic glass composites (BMGCs) reinforced with tailored volume fractions of tungsten springs were designed. The effect of tungsten springs on the compressive mechanical properties and failure modes of the BMGCs was investigated. As increasing the volume fraction of tungsten springs, the yield strength decreases slightly, however, both the fracture strength and plastic strain increase significantly. The continuity and special geometry shape of the tungsten springs are revealed to account for the enhanced fracture strength and plasticity. The BMGCs with lower volume fractions of tungsten springs exhibit a unique cone-shaped fracture morphology due to the preferential initiation of shear bands in the central metallic glass matrix. While the BMGCs with larger volume fractions of tungsten springs exhibit a mixed shear fracture morphology consisting of four distinct regions. Nevertheless, all the current BMGCs fail in a shear mode, which is obviously different from that of the BMGCs reinforced with longitudinal fibers. The failure modes of the BMGCs can be modified by designing the structure and orientation of the tungsten springs. Keywords: Bulk metallic glass composite, Tungsten spring, Deformation behavior, Failure mode