The deformability and strength of lamellar two-phase (γ and α2) TiAl intermetallic based alloy strongly depends on the lamellar interfaces in such microstructure. Molecular dynamics simulations are conducted to investigate the mechanical response and the underlying deformation mechanism of two-phase TiAl intermetallic with γ/α2 interface. Uniaxial tensile loading is applied along three different directions under “free” and “constrained” boundary conditions respectively. The evolution of dislocations and cracks has been investigated in atomic scale. The results show that the stress-strain relation exhibits strong anisotropy. Meanwhile, the dominant failure mode is plastic deformation under free boundary condition while fracture under constrained boundary condition. Moreover, the phase interface can act as dislocation source or crack source under different boundary conditions.
