Phase transformation of Cu precipitate in Fe-Cu alloy studied using self-guided molecular dynamics

self-guided molecular dynamicsによるFe-Cu合金中でのCu析出物の相変化

阿部 陽介; 實川 資朗

Abe, Yosuke; Jitsukawa, Shiro

MD計算において構造探索を効率的に促進可能なself-guided molecular dynamics(SGMD)を用いて、熱時効による鉄中での銅析出物の相変化過程を調べた。その結果、SGMD法は銅析出物中に空孔が存在しない条件下でもbccから9Rへの構造変化を再現できることがわかった。この相変化の起こる析出物サイズ(最小4.0nm)が、実験データと一致することを示した。

The self-guided molecular dynamics (SGMD) method which can enhance the conformational sampling efficiency in MD simulations, was applied in investigating the phase transformation of Cu precipitate in -iron that took place during thermal ageing. It was shown that the SGMD method can accelerate calculating the bcc to 9R structure transformation of a small precipitate (even 4.0 nm in size), enabling the transformation without introducing any excess vacancies. The size dependence of the transformation also agreed with that seen in previous experimental studies.