Microstructure Evolution of a Ti-Based Bulk Metallic Glass Composite During Deformation

The deformation behavior of Ti50Zr20Nb12Cu5Be13 bulk metallic glass composite at room temperature was investigated by uniaxial compression tests. The results indicate that the composite exhibits excellent compressive properties at ambient temperature with high fracture strength (about 2425 MPa) and outstanding plasticity (about 23%). All the true stress-strain curves of Ti50Zr20Nb12Cu5Be13 display work-hardening effect with the same tendency which decreases with the increase of the strain. The dendrite morphology almost does not change before yielding, and there are only a few shear bands in the bulk metallic glass composite after yielding. More interestingly, the plastic deformation of dendrites can be observed evidently. Before fracture, the plastic deformation of dendrite becomes more severe, and the dendrite is stretched and more shear bands appear in the composite. Combined with the fracture surface, it can be concluded that the large step shape area, plastic dimple fracture, and shear bands are the evidences of an excellent plasticity in Ti50Zr20Nb12Cu5Be13 bulk metallic glass composite.