Viscous flow behavior of bulk amorphous Zr55Al10Ni5Cu30 alloys

The viscous-flow behavior of bulk amorphous Zr55Al10Ni5Cu30 alloys has been investigated. Differential scanning calorimetry (DSC) experiments gave the activation energy for crystallization and thermal stability range of the supercooled liquid as 192.4kJ mol(-1) and 81 K, respectively. Thermomechanical analysis (TMA) experiments showed the effective viscosity decreasing monotonically with increasing temperature, approaching a constant value above the steady-state viscous-flow temperature. We confirmed that the relative displacement under compression depends strongly upon the state of amorphocity of the sample. By examining the relationship between the displacement, DeltaL, and applied stress, P, (DeltaL/P) and temperature, important information about viscous-flow forming is obtained. For secondary working with this material, we. think that applied stress Level and the values of the temperature at each stress level are very useful information. In addition, it is believed that these findings are relevant for the understanding of the effect of indentation on the bulk viscous flow. (C) 2001 Elsevier Science B.V. All rights reserved.