In situ micromechanical analysis of a nano-crystalline W-Cu composite

•Application of different complementary methods allowed insight into microstructural evolution as a function of applied deformation degree by HPT processing of a WCu alloy.•Micro-mechanical properties such as J–Integral were determined by notched cantilever experiments.•Sub nanometer precipitations were identified within nanometer-sized W grains using scanning transmission electron microscopy.•Selection of optimal deformation state leads to a beneficial microstructure and tailored mechanical properties.