For $\mathrm{NiAl}$ microalloyed by ternary elements $X=\mathrm{Cr},\mathrm{Mo},\mathrm{Ti},\mathrm{Ga}$ an ab initio density, functional approach is applied to study aspects of ductilization. By placing the alloying elements in the cleavage or slip interface planes brittle cleavage and generalized stacking fault energies are calculated for (100) and (110) interfaces. Based on two different criteria for ductile behavior our results propose that Mo and in particular Cr are promising candidates for improving ductilization of $\mathrm{NiAl}\text{−}X$ alloys.

• Received 19 December 2005

DOI:https://doi.org/10.1103/PhysRevB.73.104114