Synergistic Strengthening Mechanism and High-Temperature Microforming Behavior of FeCoNi/GO Nanocomposite

Graphene oxide (GO) has become an important reinforcing phase in metal matrix composites due to its excellent mechanical and thermal properties. However, existing studies have predominantly focused on traditional alloys or high-entropy alloys, while significant gaps remain in the investigation of synergistic strengthening mechanisms of GO and microforming behavior in medium-entropy alloys. In this article, FeCoNi/GO nanocomposites are fabricated through composite pulsed electrodeposition. GO can be efficiently incorporated into the FeCoNi medium-entropy alloy matrix, which not only markedly refines the matrix grains, effectively suppressing the excessive growth of grains during high-temperature stretching and thereby enhancing the plasticity of the composites, but also impedes the dislocation movement during the deformation process, leading to the formation of dislocation plugging and the improvement of the mechanical properties of the composites. The experimental results indicate that a moderate addition of GO can augment the tensile strength of the material up to 1657 MPa at room temperature, the elongation up to 93% at high temperature, and the maximum depth-to-diameter ratio of the microformed parts up to 0.404. This work provides a new synergistic strengthening strategy of “medium-entropy alloys + nanoreinforcing phases” for material design of microdevices in fields such as aerospace and biomedical engineering.