Anisotropic Migration of Defects under Strain Effect in BCC Iron
Ning Gao1**, Fei Gao2, Zhi-Guang Wang1
1Laboratory of Advanced Nuclear Material, Institute of Modern Physics, Lanzhou 730000 2Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Michigan 48109, USA
Abstract：The basic properties of defects (self-interstitial and vacancy) in BCC iron under uniaxial tensile strain are investigated with atomic simulation methods. The formation and migration energies of them show different dependences on the directions of uniaxial tensile strain in two different computation boxes. In box-1, the uniaxial tensile strain along the $\langle 100\rangle$ direction influences the formation and migration energies of the $\langle 110 \rangle$ dumbbell but slightly affects the migration energy of a single vacancy. In box-2, the uniaxial tensile strain along the $\langle 111\rangle$ direction influences the formation and migration energies of both vacancy and interstitials. Especially, a $\langle 110 \rangle$ dumbbell has a lower migration energy when its migration direction is the same or close to the strain direction, while along these directions, a vacancy has a higher migration energy. All these results indicate that the uniaxial tensile strain can result in the anisotropic formation and migration energies of simple defects in materials.
2017, Vol. 34 
