Modified deformation behaviour of self-ion irradiated tungsten: A combined nano-indentation HR-EBSD and crystal plasticity study

Professor Edmund Tarleton, with colleagues in Oxford Engineering and the University of Helsinki, addressed the challenge of producing self-ion irradiated implanted samples at a depth sufficient for practical research possibilities, by using a combination of experimental and modelling techniques on a self-ion implanted tungsten sample.

Using characterised samples with damage levels from 0.01 to 1 dpa, the team developed a simple crystal plasticity finite element (CPFE) model for the irradiated material.  Using data collected from transmission electron microscopy observations of similarly irradiated samples, the doses were simulated to three different doses.  

The CPFE model's predictions closely matched the experimental observations.  Predicted lattice distortions and dislocation distributions around indents agreed with corresponding measurements from high-resolution electron backscatter diffraction.

The CPFE model was used to predict the macroscopic stress-strain response of similarly irradiated bulk tungsten materials, which is key data for the design of fusion armour components.

Read the full paper, as published in International Journal of Plasticity.