Probing individual grains in polycrystals and local structure in composites and understanding the mech- anism of defect-induced changes and associated failure mechanism is of fundamental importance for the performance and longevity of structural and functional materials. To accurately predict component perfor- mance and lifetime, characterisation across multiple contributing length-scales and across a range of defor- mation regimes is required. Today’s talk will demonstrate the role of multi-scale models and multi-technique experiments in obtaining such a complete picture of material behaviour.

The demonstration will be done for the case of characterizing irradiation damage in ion-implanted tung- sten. Tungsten stands as the prime candidate for armor components in future fusion reactors, and ion- implanted tungsten serves as an effective model for simulating the radiation damage that tungsten compo- nents will encounter during reactor service. The discussion will showcase the integration of various tech- niques, including nano-indentation, atomic force microscopy (AFM), electron microscopy, high-resolution EBSD, electron channel contrast imaging (ECCI), and synchrotron X-ray Laue diffraction, to trace the dynamic changes in the properties of ion-implanted tungsten. These changes are studied in relation to factors such as defect nature, defect concentration, and crystallographic orientation. The presentation will also demonstrate the application of experimental data in the development and validation of a meso-scale crystal-plasticity (CPFE) material model. The discussion will cover the achievements and limitations of the CPFE model, emphasizing the significance of a multi-scale modeling approach. Furthermore, the advantages of this multi-scale approach will be underscored by showcasing enhancements in the CPFE model achieved through the incorporation of lower length-scale molecular dynamics simulations.

Lastly, the presentation will provide an outlook on research areas spanning hierarchically organized length and time scales. It will highlight the effectiveness of multi-scale models in such research areas for translating experimentally acquired information into the design of structural components for industrial applications.