Strengthening mechanisms in graphene reinforced Nb/Nb5Si3 composite

摘要

Understanding strengthening mechanisms is essential to tailor mechanical properties of composites. The strengthening mechanisms in graphene reinforced Nb/Nb5Si3 composite were systematically revealed for the first time, and their microstructures and mechanical behaviors were studied in detail. The compressive strength and toughness of graphene reinforced Nb/Nb5Si3 composite at room temperature stand out from the published reports, indicating that our reported strategy can enable the graphene reinforced Nb/Nb5Si3 composite to break through strength-toughness trade-off. The formed nano-Nb4C3 interfacial phase with the rod-shaped morphology is tightly bound to the graphene and embedded in the matrix of the composite, and this unique bonding form is conducive to improving the interfacial bonding strength by reducing the interfacial mismatch and forming the anchoring effect. The load transfer plays the dominant strengthening mechanism in the graphene reinforced Nb/ Nb5Si3 composite, and the load transfer for the 0.75 vol % graphene reinforced Nb/Nb5Si3 composite is five times that for the 0.25 vol % graphene reinforced Nb/Nb5Si3 composite, indicating that load transfer is significantly affected by graphene volume fraction. This work is hoped to bring some valuable information and theoretical cognition for fabricating the high-property Nb/Nb5Si3 composites in the future.

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