Numerical study of slip system activity and crystal lattice rotation under wedge nanoindents in tungsten single crystals

Abstract

Tungsten is a promising material for plasma facing components in future nuclear fusion reactors. In the present work, we numerically investigate the deformation behavior of unirradiated tungsten (a body-centered cubic (bcc) single crystal) underneath nanoindents. A finite element (FE) model is presented to simulate wedge indentation. Crystal plasticity finite element (CPFE) simulations were performed for face-centered and body-centered single crystals accounting for the slip system family {110} 〈111〉 in the bcc crystal system and the {111} 〈110〉 slip family in the fcc system. The 90° wedge indenter was aligned parallel to the [1¯01]-direction and indented the crystal in the [01¯0]-direction up to a maximum indentation depth of 2 µm. In both, the fcc and bcc single crystals, the activity of slip systems was investigated and compared. Good agreement with the results from former investigations on fcc single crystals was observed. Furthermore, the in-plane lattice rotation in the material underneath an indent was determined and compared for the fcc and bcc single crystals.