Authors: M. Namkung, S. Paik and R.A. Wincheski
Affilation: NASA Langley Research Center, United States
Pages: 419 - 418
Keywords: molecular dynamics, EAM potential, inter-metallic compounds, dispersoids
Molecular dynamics simulations were performed on the morphology of the interfaces between intermetallic nano-sized dispersoids of Ni3Al and NiAl, and a pure aluminum matrix. The lattice constants of dispersoids were initially set to be identical to that of pure aluminum. The results with the Ni3Al dispersoid demonstrate the presence of strong strain fields in the vicinity of coherent interface as the lattice constant of Ni3Al is smaller than that of pure aluminum. It is also seen that a noticeable degree of disorder is introduced in the aluminum matrix near the incoherent Ni3Al/Al interface. Hence, Ni3Al is expected to be an effective strengthener for the nanocomposite system of Ni3Al/Al. Having eight nearest neighbors, the atoms in NiAl are not as strongly bonded as in Ni3Al, where each atom is surrounded by twelve nearest neighbors, a NiAl dispersoid disintegrates by interacting with the matrix while attempting to decrease its lattice spacing during the simulation.