Intermetallic alloys with compositions near to Al67Ni8Ti25 had an ordered cubic L12 crystal structure. Features which exhibited a stacking fault-like contrast were observed on {001} planes in Al67Ni8Ti25 after homogenization annealing at 1323K. A previous study had revealed that the majority of these features were intrinsic stacking faults on {001} planes which resulted from dissociation of a<100>{001} type dislocations. Here, the characteristics of a less-prevalent type of {001} fault in the same alloy were described. Analysis showed that these faults were {001} antiphase boundaries having an associated contraction of about 0.2a normal to the plane of the fault. The partial dislocations bounding these faults had Burgers vectors of a/2<110>{001} type. The total displacement vector of this type of fault was approximately a/10)<552>. The apparent fault energy was 4mJ/m2.

Characterization of {001} Antiphase Boundary-Type Faults in an Al67Ni8Ti25 Intermetallic Alloy. W.O.Powers, J.A.Wert: Philosophical Magazine A, 1989, 60[5], 585-600