Superplastic deformation was realized on NiAl and NiAl-based alloys prepared by both common casting and directional solidification. Directionally solidified NiAl-27Fe-3Nb alloy as well as conventionally cast NiAl, NiAl-25Cr, NiAl-9Mo, NiAl-20Fe-Y.Ce, and NiAl-30Fe-Y alloys exhibited typical deformation characteristics shown in conventionally superplastic materials. NiAl and NiAl-based alloys could be divided into three categories depending on their different superplastic behavior: finely grained structure (NiAl-9Mo, NiAl-25Cr, NiAl-20.4Fe-Y.Ce, NiAl-30Fe-Y), coarsely grained structure (NiAl), and columnar structure (NiAl-27Fe-3Nb). The corresponding deformation mechanisms for fine-grained structure, coarsely grained structure, and columnar structure were grain boundary sliding or grain boundary sliding accompanied by dynamic recrystallization, dynamic recovery and recrystallization, and intragrain dislocation slip, respectively.

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