It cannot react with strong acid and alkali, with Mohs hardness of 9.36, microhardness of 5400-6300 kg/m2, density of 2.52 kg/m2 and melting point of 2450 degrees Celsius. Boron carbide is hexagonal dark black, and boron carbide is mainly used as an additive in refractories. Wear-resistant covered electrode and other advanced anti-oxidation, high-temperature and wear-resistant products. Densified boron carbide is made into sandblasting nozzle, mechanical seal and bulletproof material. Because boron carbide has a large thermal neutron capture cross section, it can absorb a large number of neutrons and can be used in high-tech fields such as nuclear reactors.