Abstract
Intermetallic alloys with compositions near Al67Ni8Ti25 have the cubic L12 crystal structure, in contrast with Al3 Ti which has the tetragonal D022 structure. Features exhibiting stacking-fault-like contrast were observed on {001} planes in an Al67Ni8Ti25 intermetallic alloy after annealing at 1050°C. Characterization of the features using transmission electron microscopy revealed that they are intrinsic stacking faults on {001} planes, which result from dissociation of a0<001>{001} dislocations. The displacement vector associated with the faults was determined to be approximately 0.4a0<001>. Computer-simulated electron micrographs were instrumental in identifying the fault characteristics. The fault characteristics reveal that they are sessile and thus do not directly participate in deformation processes in this intermetallic alloy.