Viscous flow of Cu₅₅Zr₃₀Ti₁₀Co₅ bulk metallic glass in glass-transition and semi-solid regions

The viscous flow behavior of Cu₅₅Zr₃₀Ti ₁₀Co₅ metallic glassy samples was investigated on heating by a mechanical testing machine in accordance with the phase transformations taking place in the alloy. Phase transformations were studied by various methods, including differential calorimetry and electron microscopy. It was found that glassy samples demonstrated a relatively low viscosity of ∼10⁹ Pa s and did not lose their ability to be deformed under a relatively low stress of 5 MPa during the crystallization process until complete crystallization had occurred, thus producing in situ glassy/crystal composites.