Dense sintered boron carbide

Sdicon carbide, hot pressed Alumina, dense sintered Boron nitride, hot pressed Sdicon nitride, hot pressed Boron carbide, hot pressed... 

The only technically important sintering additive for boron carbide is carbon, as discovered almost simultaneously by Schwetz and Vogt [189], Henney and Jones [190], and Suzuki et al. [191], which today allows the routine production of dense parts. An amount ranging from 1 to 6 mass-% is sufficient to obtain almost theoretical density. Schwetz and Grellner [192] added phenolic resin (corresponding to 1-3 mass-% C) to a submicron B4C powder and obtained >98% density at 2150°C. The resins are pyrolized at temperatures up to 1000°C and they leave a... 

ESK (Elektroschmelzwerk Kempten GmbH) (1995) Method of making polycrystalline dense shaped bodies based on boron carbide by pressureless sintering. European Patent EP 19940109275. 

As with silicon nitride, solid forms of silicon carbide are made by one of three processes sintered, hot-pressed, or reaction-sintered. Sintering requires use of an additive such as alumina, carbon, or boron to promote liquid-phase sintering. Hot pressing is done at 2000°C and results in a very hard, dense material. Reaction sintering occurs when a mixture of SiC powder and carbon is heated in contact with molten silicon. The reaction results in a nearly complete conversion to SiC, although according to Schwartz, most materials made by this process contain an excess of carhon or silicon. ... 

---