One-step synthetic route and sintering for carbon-coated B4C nanoparticles

Boron carbide is an extremely hard material extensively used in the industry. In this study, carbon-coated B4C nanoparticles were synthesized through a one-step synthesis method using high-temperature firing cheap and readily available raw materials, namely, boric acid and sucrose. X-ray diffraction and Raman spectra analysis indicated the formation of B4C, and high-resolution transmission electron spectroscopy revealed that the carbon-coated B4C nanoparticles exhibited regular B4C-C core-hell structure with an average particle diameter of around 100 nm. This method is simple and time-saving, and can be adopted for the large-scale production of the core-shell nanoparticle. Directly using these core-shell structural nanoparticles as precursor, high-performance B4C/C ceramics with hardness reaching 34 GPa, fracture toughness reaching 3.3 MPa m1/2 were synthesized. This study has important implications in developing high-performance B4C ceramics.