Published online by Cambridge University Press: 28 February 2011
Using an Embedded Atom Method calculation of the interatomic potentials and volume forces in the Ni-Al alloy system, we have examined the plastic and elastic response of an ordered bcc Ni-Al crystal with a pre-existing crack under Mode I loading at various temperatures, stresses and crystal orientation. Depending upon those conditions we found evidence of slip and dislocation generation near the crack tip concomitant with crack propagation. we also saw evidence of a brittle to ductile transition above a certain temperature which is manifested by copious slip and dislocation production. Atomic arrays up to 4000 atoms have been studied.