Critical cooling rates for amorphous-to-ordered complexion transitions in Cu-rich nanocrystalline alloys

Amorphous complexions in nanocrystalline metals have the potential to improve mechanical properties and radiation tolerance, as well resistance grain growth. In this study, stability of amorphous binary ternary Cu-based alloys is investigated by observing effect cooling rate from high temperature on occurrence amorphous-to-ordered complexion transitions. Bulk Cu-Zr Cu-Zr-Hf alloy samples were annealed induce boundary premelting then quenched through a procedure that induces gradient local sample height. thickness distributions found be invariant alloy, demonstrating enhanced structure compared which had thinner regions slowly cooled. The experimental results are used construct time-temperature-transformation diagrams for transition both alloys, enabling deeper understanding influence chemistry critical necessary avoid transitions at least three orders magnitude slower than alloy.