Observations of the fine structure of superdislocations in Ni3Al by field-ion microscopy
- 1 December 1974
- journal article
- research article
- Published by Taylor & Francis in Philosophical Magazine
- Vol. 30 (6) , 1379-1394
- https://doi.org/10.1080/14786437408207288
Abstract
The fine structures of two common types of superdislocation which exist in the intermetallic Ni3Al are experimentally characterized by field-ion microscopy. It is shown how the a type superdislocations and the a/3 type superlattice partial dislocations may be distinguished in the field-ion image and the geometrical contrast theory is extended to include these observations. The a type super-dislocations are found to be dissociated, having a fault width of close to 3 nms, and the antiphase boundary energy is hence calculated to lie between 0·25 and 0·35 Jm-2. The a/3 type dislocations do not appear to be dissociated in the classical sense. The possibility of distinguishing between an intrinsic and an extrinsic stacking fault in this alloy is demonstrated and an example is given of the contrast from a dislocation pile-up. Finally, the observations of dislocations, and ordering defects in field-ion images from ordered alloys are discussed.Keywords
This publication has 20 references indexed in Scilit:
- Measurements of relative bond energies in some ordered nickel-based alloys by field-ion microscopyPhysica Status Solidi (a), 1973
- A field-ion microscope study of ion-implantation in iridium II. results and discussionPhilosophical Magazine, 1972
- Principles Underlying the Behavior of Passing DislocationsJournal of Applied Physics, 1972
- Fieldion microscopy of frank loops in platinum: Computer simulation and experimental observationPhilosophical Magazine, 1970
- Characterization of stacking faults with the field-ion microscopePhilosophical Magazine, 1970
- Investigations of dislocation strain fields using weak beamsPhilosophical Magazine, 1969
- Viscous slip in the L12 latticeScripta Metallurgica, 1969
- On intrinsic/extrinsic stacking fault pairs in the Ll2 latticeScripta Metallurgica, 1969
- Field-Ion Microscopy of CobaltJournal of Applied Physics, 1967
- The interpretation of field-ion micrographs: The image from an order/disorder alloyPhilosophical Magazine, 1966