Thermally introduced planar faults were investigated in the binary alloy, and in ternary alloys (with added B, Cr, Pd or W), by using transmission electron microscopy. It was found that air-cooling of the alloys from 1273K, followed by annealing (698K, 120h), introduced 2 types of planar fault. One type was an antiphase boundary, which was observed in all of the alloys. The other type was a complex planar fault, which had both antiphase boundary and stacking fault characteristics, and was observed only in B-containing alloys. The formation of the antiphase boundaries was suggested to arise from the collapse of the lattice due to vacancy condensation on triple layers of {111} planes. The size, distribution and planarity of the antiphase boundaries were affected by additions of ternary elements.

K.Yoshimi, S.Hanada, T.Onuma, M.H.Yoo: Philosophical Magazine A, 1996, 73[2], 443-56