205 分子動力学法によるナノサイズ Ni-Ti 合金の挙動解析と原子間ポテンシャルの評価  [in Japanese] Molecular Dynamics Study on Behavior and Interatomic Potential of Nano-scale Ni-Ti Alloy  [in Japanese]

Thin film Ni-Ti alloy is known as micro actuator that has unique structural property and behavior. To investigate these properties by computational atomistic simulation, at first, we evaluate interactions in Ni-Ti alloy by using EAM potential function. We calculate potential energy of B2,L1_0 and strained B2 (as B19) structures at Ok. Among these structures, B2 is the most stable. Secondly, we evaluate behavior of nano-scale Ni-Ti alloy by molecular dynamics simulation. In uniaxial tensile simulation of B2-structured-Ni-Ti monocrystal composed of 11774 atoms, it is observed that sudden stress relaxation occurs. After detecting 0 stress situation, we simulate heating process. Then increase of stress and recovery of lattice structure which are of almost B2 structures are observed. These behaviors show possibility of shape memory effect in nano-size Ni-Ti alloy.