Control of the phase composition and morphology of a Cu‐Sb eutectic alloy via liquid‐liquid structure transition

Abstract

The current paper focuses on the solidification characteristics of a Cu‐Sb eutectic alloy in its different liquid states. Liquid alloy resistivity‐temperature patterns suggest an irreversible temperature‐induced liquid‐liquid structure transition (TI‐LLST), and a reversible TI‐LLST occurred during the heating‐cooling runs. A set of solidification experiments was conducted based on the results. The irreversible TI‐LLST caused an enhanced solidification undercooling, increased solidification rate, refined regular eutectic morphologies, and absence of a pre‐eutectic Cu2Sb phase. The reversible TI‐LLST resulted in different phase compositions and eutectic structures. The mechanisms behind these transitions are also briefly discussed.

Indication of liquid-liquid phase transition in CuZr-based melts

“…The present work, as well as some relevant works (see Refs. 15,25,and 48), suggests that the LLPT phenomenon often occurs in the alloy melts with a large percentage of Cu. Thus, in the future work it is necessary to carefully explore the dynamics in the Cu-rich melts well above T l , especially when the F-S transition phenomenon is involved.…”

“…The similar reversible LLPT phenomenon has been reported in CuSb melts, in which the irreversible phase transition was likewise observed above T l only in the first upscan. 25 It has been verified that the irreversible phase transition is related to the supercooling degree and the growth rate of crystallites upon the solidification, whereas the reversible LLPT leads to different phase compositions and microstructures. This interpretation accords well with our observation in Fig.…”