title: Shear-coupled grain boundary migration assisted by unusual atomic shuffling.
abstract: Shear-coupled grain boundary (GB) migration can be an efficacious mechanism to accommodate plastic deformation when the grain size of polycrystalline materials goes small. Nevertheless, how this kind of GB motion comes into play at the atomic level has not been fully revealed. Here, we have investigated the shear-coupled migration (SCM) of typical [100] group symmetrical tilt GBs in bcc W using atomistic simulations. Depending on GB character, the SCM is found to proceed via dislocation slipping in the 〈100〉 or 〈110〉 mode with striking shear strength difference between them. We demonstrate that there exists an unusual atomic shuffling along the tilt axis, which greatly assists SCM to operate in the easier 〈110〉 mode instead of the 〈100〉 one. The present results highlight the significant role of GB character in the atomistic SCM process and contribute to the future design and fabrication of high-performance materials in GB engineering.
authors.affiliation: Department of Physics, Beihang University, Beijing 100191, China.|Department of Nuclear Engineering and Radiological Science, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Liang-Liang
authors.initials: LL
authors.lastname: Niu
authors.affiliation: Department of Physics, Beihang University, Beijing 100191, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Physics, Beihang University, Beijing 100191, China.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Shu
authors.affiliation: Department of Nuclear Engineering and Radiological Science, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.affiliation: Department of Physics, Beihang University, Beijing 100191, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Jin
authors.affiliation: Department of Physics, Beihang University, Beijing 100191, China.
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Zhou
authors.affiliation: Department of Physics, Beihang University, Beijing 100191, China.
authors.forename: Guang-Hong
authors.initials: GH
authors.lastname: Lu