Graphene-decorated bimodal pure metal with high strength and ductility

Heterostructured design and microcrack management mitigate the strength-ductility dilemma in metallic materials. Here, we demonstrate a simultaneous enhancement of strength and ductility in graphene-decorated bimodal pure nickel, achieving a strength increase to 1 GPa and an 18% improvement in elongation by designing heterostructure with graphene, metal powders, and metal foams. The results show that grain refinement, hetero-deformation-induced hardening, and activated stacking faults mainly cause the strength-ductility synergy. Additionally, while dispersed microcracks nucleate within the fine grain zones, their propagation is constrained by the coarse grain zones. This study provides new insights into improving the strength-ductility combination in metallic materials.