 boron carbide (chemical formula approximately b4c) is an extremely hard boronâcarbon ceramic material used in tank armor, bulletproof vests, engine sabotage powders, as well as numerous industrial applications. with a mohs hardness of about 9.497, it is one of the hardest materials known, behind cubic boron nitride and diamond. boron carbide was discovered in 19th century as a by-product of reactions involving metal borides, however, its chemical formula was unknown. it was not until the 1930s that the chemical composition was estimated as b4c.ridgway, ramond r "boron carbide", european patent ca339873 (a), publication date: 1934-03-06 there remained, however, controversy as to whether or not the material had this e
Boron_compounds Carbides Neutron_poisons Superhard_materials