Effect of strain on solution energy of hydrogen in alpha-zirconium from first-principle calculations

摘要

The solution energy of hydrogen has been obtained by performing the first-principle calculations when the volumetric strain, biaxial strain, and shear strain are applied to the alpha-Zr lattice, respectively. The results show that the points of intersection between the curves of the solution energy of hydrogen at the tetrahedral interstice site and octahedral interstice site appears under the volumetric strain of 0.5% while it appears under the biaxial strain of 1.55%. The solution energy changes periodically with the shear strain directions when the shear strain is applied to different crystal planes. After the comparison of the solution energy under the volumetric strain and shear strain, the volumetric strain affects the solution energy of the hydrogen in the alpha-Zr lattice more significantly than the shear strain. Further, hydrogen atoms tend to gather in the tensile strain region rather than the shear strain region with the same value of strain. Hydrogen atoms accumulate at the vicinity of the screw dislocations on the prism plane could reduce the strain rate sensitivity of hcp lattice. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.