Effects of liquid–liquid transition on solidification of Sb–10 wt-%Cu alloy

Abstract

The electrical resistivity of the liquid Sb–10 wt-%Cu alloy as a function of temperature was measured using direct current four probe technique. In a relatively high temperature zone above the liquidus, the resistivity–temperature (ρ – T ) curves of the melt change abnormally; moreover, the changing pattern in the first heating process is completely different from the ones in the subsequent heating and cooling cycles. Since resistivity is a structural sensitive parameter, these abnormal changes of ρ – T curves indicate that the temperature-induced liquid–liquid structure transitions (L-LSTs) probably occur in Sb–10 wt-%Cu melt, with some reversible characters. To explore the effects of the L-LST on the solidification behaviours and solidified microstructures of this alloy, solidification experiments were further carried out according to the temperature ranges with anomalous changes on ρ – T curves. Results show that after the melt experienced the L-LST, larger undercooling, shorter solidified time and much finer microstructures with differently microscopic patterns could be obtained.

Keywords:

• LIQUID–LIQUID STRUCTURE TRANSITIONS (L-LST)
• UNDERCOOLING
• SOLIDIFIED MICROSTRUCTURE
• SB–10 WT-%CU ALLOY