Ductility of undoped Ni₃Al

Ductility of binary Ni3Al alloys having Al concentrations ranging from 23 to 26 mol% has been investigated using tensile tests. It was found that a recrystallized Ni–23Al alloy exhibits elongation of approximately 5%. Recrystallized Ni–23∼26Al alloys prepared in the present investigation were confirmed to be γ′ single phase by optical and transmission electron microscopy. Elongation of recrystallized alloys decreases with increasing Al concentration from 23 mol% to stoichiometry and recrystallized alloys containing more than 25% Al exhibit almost no elongation at 290 K. This ductilization behavior in Ni-rich Ni₃Al alloys is explained by considering both Ni segregation to grain boundaries and decrease in ordering energy, caused by deviation away from stoichiometry.