Study of viscosity of Fe-Cr melts containing 2 to 40 at % of chromium

Abstract

The temperature, time, and concentration dependences of viscosity ν of Fe-Cr melts containing 2 to 40 at % of chromium are studied. It is shown that the observed anomalies in viscosity polytherms in the first heating mode and the hysteresis of ν in subsequent cooling are due to the slow setting of thermodynamic and chemical equilibrium in the system of crucible-melt-atmosphere, which is shifted to higher tempera tures with increasing oxygen content in the alloy. The minimum and maximum of viscosity are observed at 5 and 12 at % of Cr, respectively; they are caused by a concentration change in the binding energy between the atoms, which is determined by the geometric and compositional short range order. The nonequilibrium state of the melts has no significant effect on the nature of their viscosity isotherms.

Semi-empirical equation for the estimation of viscosity of liquid metal alloys of eutectic composition

“…The model presented has been verified also for other systems at eutectic compositions but the results are not reported in this work because the discrepancy between the experiments performed with different methods by different researchers is too high (up to 70%), even though interesting studies have been conducted in these years (e.g. [11][12][13][14][15][16][17][18][19][20]). …”