Orientation dependence of the nano-indentation behaviour of pure Tungsten

image of 3d deviatoric strain tensor near indents in varying orientations and a pure tungsten single crystal

Researchers in the Materials Science and Engineering departments at Oxford report, in this paper, published in volume 189 of Scripta Materialia, on the orientation dependence of residual lattice strain patterns and dislocation structures in tungsten.  


For orientations with one or more Burgers vectors close to parallel to the sample surface, dislocation movement and residual lattice strains are confined to long, narrow channels.  Coupling of nano-indentation and crystal plasticity finite element simulations is unable to reproduce this behaviour, and the researchers' analysis reveals the responsible underlying mechanisms.