Planar defect energies at the ground state in L10 TiAl were calculated using the embedded atom method. The results showed that the magnitudes of the defect energies in a {111} plane were in descending order: antiphase boundary, complex stacking fault, intrinsic stacking fault. The antiphase boundary energy varied, depending upon the plane of the antiphase boundary. The antiphase boundary energy decreased when the antiphase boundary underwent cross-slip from the (111) plane onto either the (101) plane or the (010) plane. The calculated antiphase boundary energies for the (111), (101) and (010) planes were 322, 237 and 131mJ/m2, respectively. The equilibrium energies of various dissociated super-dislocations were calculated on the basis of the balance between the repulsive energy among the partial dislocations, and the attractive energy originating from planar defects. The results showed that the super-dislocations (b = a[101]) which were dissociated on two different {111} planes, or on one {111} plane and one non-{111} plane, had lower energies than those exhibiting co-planar dissociation.

Planar Defect Energies by the Embedded Atom Method and Dissociated Superdislocation Configurations in the L10-Type TiAl Compound. Z.C.Li, S.H.Whang: Materials Science and Engineering A, 1992, 152[1-2], 18-25