Oxidation-resistant boron-linked strengthened graphene-based composite

Abstract

Direct sintering graphene powders into macro-scale and high-performance graphene-based composites presents a significant challenge due to high melting point of graphene. Besides, the problem of high temperature oxidation and ablation of graphene restricts its application. Here, centimeter-scale graphene composites were fabricated from boron nanoparticles and self-propagating high-temperature synthesis (SHS) graphene by spark plasma sintering (SPS). The B-C bonds and Y-type carbon structures are composed of covalent bonds, exhibiting stronger interactions than the conventional interfacial interactions and benefiting to improve the mechanical properties of graphene-based composites. Thus, the boron-graphene composite presents an exceptional flexural strength (309 MPa), superior compressive strength (487 MPa) and remarkable microscale compressive strength (6.25 GPa). It also exhibits outstanding oxidation resistant (the weight loss was only 0.2 % after oxidized at 1000°C). Furthermore, we employed molecular dynamics (MD) simulations to understand the strengthening mechanism conferred by boron linkage. The high-performance boron-graphene composites are lightweight, easy to prepare, and cost-effective, rendering them uniquely advantageous for practical applications across various fields.