The configuration of super-dislocations in the γ′-Pt3Al phase of a Pt-based superalloy was evaluated following high-temperature tensile creep deformation. Weak-beam dark-field transmission electron microscopy was used to measure the dissociation width of super-dislocation partials. Short straight segments of dissociated dislocations with <110>-type Burgers vectors were observed. Dissociation took place on {111} planes, with a separation of the partials between 3.4 and 4.5nm, resulting in antiphase boundary energies of 344 to 456mJ/m2 considering elastic anisotropy. The dislocations were of mixed edge and screw type and had a planar configuration. First-principles antiphase boundary energy calculations for stoichiometric Pt3Al revealed that the energy of {111} boundaries was 205mJ/m2, and the {010} energy was 414mJ/m2.

Configuration of Superdislocations in the γ′-Pt3Al Phase of a Pt-Based Superalloy. C.H.Liebscher, U.Glatzel: Intermetallics, 2014, 48, 71-8