Evidence of recrystallization mechanism of grain refinement in hypercooled Co ₈₀Pd ₂₀ alloys

Applying fluxing method, hypercooling was achieved in Co ₈₀Pd ₂₀ alloys. The microstructures and substructures of the as-solidified hypercooled Co ₈₀Pd ₂₀ alloys subjected to rapid quenching and natural cooling were investigated. Compared to the naturally cooled specimens showing typical microstructural characteristics of recrystallization, high densities of low-angle grain boundaries, dislocations and stacking faults were observed in the quenched specimens. These sub-structures suggest a partial recrystallization occurring in the quenched specimens and are believed as the evidence of recrystallization mechanism of grain refinement in hypercooled Co ₈₀Pd ₂₀ alloys. The relatively defect-free structure and the high-angle boundaries suggest a relatively sufficient recrystallization in the naturally cooled alloys.