Grain boundary structure in Ni3Al

The multiplicity of possible grain boundary structures was studied for the ordered compound Ni3Al. Two symmetrical tilt boundaries were chosen for the detailed study corresponding to Sigma = 3 < 110 > {112} and Sigma = 9 < 110 > {114}. These boundaries were investigated considering possible variations of the local chemical composition and environment using atomistic computer simulation with EAM interatomic potentials. Many different grain boundary structures were found having very similar energies for the same orientation of the two crystals and the grain boundary plane. Possible transformations among these structures may result from the interaction of the boundaries with dislocations or antiphase boundaries. The role of the multiplicity of structures and these transformations in the grain boundary mechanical properties is discussed. In this paper, we explore the role that different possible grain boundary structures play in intermetallic alloys.