ATOMISTIC SIMULATION OF POINT DEFECTS IN NiAl ALLOY

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Using Embedded Atom Method(EAM) potential and molecular static relaxation method, the formation energies of vacancies, antisites, di vacancies in NiAl alloy have been calculated and the relaxation of atoms around the point defects have been investigated. Results show that it is very difficult to form Ni antisite and to form vacancies with the same type of atoms in the nearest neighbor in NiAl intermetallics, the Al sublattices are always be occupied; and when the alloy is Ni rich, the Ni atom resides at Al sublattice and forms Al antisite, however if the alloy is Al rich, Ni vacancies are formed. The vacancy interaction distance is limited to a few interatomic distance.