High-temperature creep deformation of coarse-grained boron carbide ceramics

Boron carbide (B4C) is a promising ceramic as it possesses a unique combination of properties. While the room-temperature mechanical properties of pure B4C have received considerable attention because of its high hardness and resistance to shock-impact, its high-temperature mechanical properties remain unexplored. To that end, creep deformation of coarse-grained, dense B4C has been studied under uniaxial compression in the stress range 250–500 MPa and the temperature range 1600–1800 °C. It has been found that B4C deforms extensively without failure, with a stress exponent n ∼ 3 and an activation energy Q ∼ 632 kJ/mol. These data, together with the extensive microstructural characterization of the deformed specimens, are used to gain insights into the creep mechanisms operative in B4C.