Researchers from Oxford Materials and Forschungszentrum Jülich used micromechanical tests to investigate the mechanical properties of a novel iron/tungsten (Fe/W) functionally graded (FG) composites in fusion-relevant conditions. Their paper in Materials & Design revealed failure of the Fe/W FG composites can occur due to the formation of brittle interfaces (Fe7W6) during operation of a fusion reactor. Micromechanical testing (nanoindentation & micro-cantilever bending tests) is a useful characterisation technique, providing both evaluation of mechanical properties and improved understanding of the failure mechanism in operation environment.