Synthesis of a superhard ceramic in the ternary Boron-Carbon-Silicon system from unchartered Pressure and Temperature range

Boron carbide (B4C) is a superhard ceramic with applications in various industrial fields, including engineering tools, the nuclear industry, safety armors, and more. However, it exhibits a gradual loss of strength beyond its Hugoniot elastic limit, attributed to the formation of boron vacancies within the C-B-C chains along the c-axis under mechanical stress. To extend its plastic regime to higher constraints, the proposed approach is to strengthen the C-B-C chains that link the icosahedra of B4C. The objective is to substitute Boron atoms in the chains with Silicon using high pressure and high temperature (HP-HT). Thus, our aim is to investigate the HP-HT synthesis of Si-doped B4C phase, ensuring the absence of parasitic Si-C or Si-B compounds, through the direct reaction between molten Silicon and solid Boron carbide. This synthesis will be performed under HP-HT conditions where Silicon is liquid, preventing the formation of unwanted compounds.