ATOMISTIC SIMULATION OF FRACTURE IN TIAL

Atomistic simulations of fracture in L1(0) TiAl were carried out using embedded atom method (EAM) interatomic potentials and molecular stati cs. We studied the behavior of semi-infinite cracks under mode I loadi ng in different orientations of the crack front and plane. For the [0 (1) over bar 1](111) orientation, we observed dislocation emission inv olving the formation of superlattice intrinsic stacking fault (SISF). For the [001](110) orientation, we observed the emission of ordinary 1 /2[110] edge dislocations that were highly mobile and had a compact co re. We found that cracks with [001](100) orientation cleaved near the Griffith value of loading in a purely brittle manner. Similar behavior was observed for cracks with [01 (1) over bar](100) orientation.