Atomic probe field ion microscopic investigations were made of antiphase boundaries and super-dislocations in B2-ordered alloys which contained 2at%Cr. An a/2<111>{123} antiphase boundary was detected in Ni-rich Ni50Al48Cr2 alloy which contained higher local concentrations of segregated Cr atoms. The Cr atoms exhibited a strong site preference for the Al sub-lattice. The Cr atoms therefore replaced Al atoms. Super-dislocations without any significant Cr enrichment were imaged. No dissociation into partial dislocations was detected, due to the high antiphase boundary energy.

Atom Probe Field Ion Microscopy Investigations of Antiphase Boundaries and Super-Dislocations in NiAl Alloyed with Chromium. R.Fischer, G.Frommeyer, A.Schneider: Physica Status Solidi A, 2001, 186[1], 115-21