Effect of Zr addition on metastable Liquid-Liquid Phase Separation of Cu-Fe alloys

The liquid-liquid phase separation (LLPS) behavior was investigated in Cu-Fe alloys that consisted of 60 wt % or 80 wt % Cu and balance iron, without or with addition of 1 wt% Zr. Both Zr-free alloys clearly showed LLPS at metastable spinodal temperatures prior to gamma-Fe nucleation, whereas Zr-added showed gamma-Fe phase evolution without LLPS. Addition of Zr was highly effective to activate gamma-Fe nucleation by decreasing the mixing enthalpy and also accelerating heterogeneous nucleation. A combination of thermal instrumental analysis and classical nucleation theory yielded an effective assessment made of LLPS behavior below the liquidus temperature of Cu-Fe alloys. Furthermore, it was possible to control the solidification mechanism of Cu-Fe alloy by zirconium addition. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

Addition of Zr in Cu-Fe alloys was found to effectively activate γ-Fe nucleation and suppress liquid-liquid phase separation. A combination of thermal instrumental analysis and classical nucleation theory allowed for an effective assessment of LLPS behavior in Cu-Fe alloys.