Bicontinuous structures, characterized by interpenetrating and continuous phases, offer an opportunity to simultaneously improve the strength and deformability of alloys. However, introducing substructures that incorporate nanograins and nanotwins into both phases of the bicontinuous structure remains a significant challenge. Here, a hierarchical bicontinuous nanocomposite was constructed in a Pb-50 at% Al immiscible alloy by high-pressure torsion (HPT), consisting of an interlocked Pb/Al network with intra-phase nanograins and abundant nanotwins within the Pb grains. The resulting nanocomposite exhibits a high strength of 183 MPa, attributed to the synergistic strengthening from both grain boundaries (GBs) and phase boundaries (PBs). Moreover, the combination of bicontinuous networks and nanotwins effectively modulates dislocation motion, promoting homogeneous plastic deformation without the formation of shear bands during micropillar compression. These findings provide a promising strategy for enhancing the mechanical properties of bicontinuous metallic systems.
Chen et al. (Sun,) studied this question.