Open AccessMicroscopic studies of structural transition in iron under one-dimensional strain
Author(s) -
Jian-Li Shao,
He An-Min,
Qin Cheng-Sen,
Pei Wang
Publication year - 2009
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.58.5610
Subject(s) - materials science , softening , phase transition , nucleation , phase (matter) , hardening (computing) , crystal (programming language) , isothermal process , condensed matter physics , thermodynamics , composite material , chemistry , physics , organic chemistry , layer (electronics) , computer science , programming language
Molecular dynamics simulation employing an embedded-atom-method potential is performed to investigate the body-centered cubicbcc-hexagonal close-packedhcp structural transition in single crystal iron induced by isothermal compression along 001 divection. Above the critical strain of transition, homogeneous nucleation of hcp phase appears and grows into flakes along the 011 face. The elastic constants C31 and C32 harden during the compression in bcc phase, while C33 undergoes a softening prior to the transitionall the elastic constants increase rapidly with compression after the system entering the hcp phase. Increasing temperature can weaken the hardening and softening process of C33, but affect the stress threshold of transition only weakly. Hcp twins are formed at 300 K, leading to the shear of crystal latlice. For the mixed phase, the potential of hcp phase is greater than that of bcc phase, hcp phase shows an over-relaxation of the stress, and the longitudinal partial stress keeps linearly decreasing with hcp mass fraction throughout the transition.