Molecular Dynamics Study of the Microstructure of Near Grain Boundary Distortion Region in Small Grain Nano-NiAl Alloy

Using the molecular dynamics simulation method, the microstructure of the distortion region near the curved amorphous-like grain boundary in nano-NiAl alloy is studied. The results show that due to the internal elastic force of high energy grain boundary, a distortion layer exists between grain and grain boundary. The lattice expansion and the decreasing structure factor are observed in this region. Stacking fault in samples with grain size 3.8 nm is clearly observed across the distortion region at the site very close to grain. The influences of different grain sizes on average distortion degree and volume fractions of the distortion region, grain and grain boundary are also discussed.