Spark plasma sintering of B 4C ceramics: The effects of milling medium and TiB 2 addition

Abstract

Boron carbide (B 4C) ceramics, with a relative density up to 98.4% and limited grain growth, were prepared at 1600–1800 °C by spark plasma sintering (SPS) technique. The effects of powder milling medium (water and 2-propanol) on the powders' surface characteristics and TiB 2 addition on the sintering densification were investigated. The ball milling processing of B 4C powders in water can promote the sintering of B 4C ceramics. A B 2O 3 layer on B 4C particle surface is concluded to promote the densification of the B 4C ceramics at an early sintering stage. This B 2O 3 layer, which normally inhibits the densification process at the final stage of the sintering, can be reduced through reaction with TiB 2 particles, resulting in further densification of the B 4C ceramics.