Melt viscosity of nanocrystalline alloys in the model of free volume

Nanocrystalline Soft Magnetic Iron-Based Materials from Liquid State to Ready Product

“…Since after cooling the viscosity of the melts does not recover to its initial value, it can be concluded that the melt underwent irreversible changes. The viscosity of Fe 73.5 Cu 1 M 3 Si 13.5 B 9 melts with various inhibitors correlates well with the free volume [36]. The Nb melt has the largest free volume, while the Mo melt has the smallest.…”

“…The reason for the oscillations can be a transition from a non-equilibrium melt structure inherited from the initial crystalline phases to an equilibrium state, or random oscillations associated with the periodic appearance and destruction of cluster structures, or an intense structural transformation of the melt [35]. Figure 4 shows the kinematic viscosity in logarithmic scale and absolute temperature in the inverse scale for Fe 73.5 Cu 1 M 3 Si 13.5 B 9 melts with different inhibitors M = Nb, Mo, V, Cr at the stage of heating (a) and cooling (b) [36]. At the heating stage, the temperature dependences of melts with Nb, Mo, and V have two linear sections, the slope of which changes at the critical temperature T k = 1770 K. In a melt with Nb, the activation energy increases upon going to the high-temperature region.…”

“…At the cooling stage, linear dependences were obtained in the entire temperature range for all melts. Table 1 shows the calculated values of the activation energy E a for melts with various inhibitors [36]. In the low-temperature region, a melt with Nb has the lowest E a = 21 kJ•mol −1 , and a melt with Mo has the highest one, E a = 47 kJ•mol −1 .…”

“…Temperature dependences of the kinematic viscosity ν for nanocrystalline Fe 73.5 Cu 1 M 3 Si 13.5 B 9 alloys with different inhibitors M = Nb, Mo, V, Cr at the stage of heating (a) and cooling (b). Reproduced with permission from[36].…”

“…Activation energy of viscous flow for Fe 73.5 Cu 1 M 3 Si 13.5 B 9 melts with different inhibitors M = Nb, Mo, V, Cr. Reproduced with permission from[36].…”