Influence of Undercooling on the Non-equilibrium Solidification Process and Microstructure of Cu-Ni Alloys

Abstract

By applying the rapid solidification technique of deep undercooling, Cu65Ni35 and Cu60Ni40 alloys achieved maximum undercoolings of 284 and 222 K, respectively. Microstructural images captured reveal grain refinement in both alloys across both large and small undercooling ranges. High-speed photography was used to analyze the relationship between solidification front morphology and undercooling, showing that dendrite remelting and fragmentation caused grain refinement under small undercooling, while stress-induced recrystallization is responsible under large undercooling. Microhardness testing further demonstrates a sudden drop in microhardness near the critical undercooling point, providing evidence for grain refinement due to recrystallization in large undercooling tissues.

Keywords

undercooling / microstructure / grain refinement / solidification rate

RIGHTS & PERMISSIONS

Wuhan University of Technology and Springer-Verlag GmbH Germany, Part of Springer Nature