Embedded-atom interatomic potentials and simulation of planar defects in intermetallic Ti 3 Al

Electron microscopic study of Ti3Al microstructure after deformation at 1073–1273 K

“…The recombination of partial dislocations is a thermally activated process, which takes place at elevated temperatures. The process of the cross slip of an a/2 superpartial dislocation to the prism plane is energy favorable since the energy of the antiphase boundary in the prism plane is much lower than its energy in the basal plane ( (1 1 0 0) = 6 mJ/m 2 , (0 0 0 1) = 161 mJ/m 2 [14]). The cross slip of a superdislocations was observed experimentally (Fig.…”

“…1). The change in the distribution of a superdislocations in the basal plane can be analyzed taking into account specifics of the core structure of these dislocations as determined from computer simulation [14,15]. Each of the a/2 superpartial dislocations is split into two Shockley partial dislocations limiting the ribbon of a complex stacking fault.…”

Fracture behaviour of Ti3Al single crystals for the basal slip orientation

“…When the change of configuration 7d to configuration 7e occurs the energy lowers due to the change of a planar defect type (CSF (0001) ! APB (0001) ), because the energy of complex SF is lower than the energy of APB in basal plane [11,12]. Similarly, the lowering of the energy while the configuration 7f changes to configuration 7g is determined by SF ( 1100) !…”

“…[14], however, the Burgers vector magnitudes of the partials were not determined. As a result of computer modelling [11], the Burgers vectors of the partial dislocations were found to be equal to 1=12½ 2110: These Burgers vectors were used in reactions (2a) and (2b).…”

“…In the previous paper [9], the structure and energies of a-superdislocations of different orientations with 1/3k11 20l Burgers vector in basal plane was determined by molecular dynamics calculations, having N-atom interaction potentials for Ti 3 Al found by the embedded atom method [10,11]. The analysis of the results from computer modelling of screw, 308, 608 and edge superdislocations in basal plane, separated by an anti-phase boundary (APB), shows that the changes in partial core structure are to be observed only for superdislocations of screw orientation (Fig.…”