In recent years, advanced ceramics have shone brightly on the military stage. With high specific stiffness, high specific strength, and chemical inertness in many environments, advanced ceramic protective armor has the characteristics of strong intrusion resistance, portability, and high comfort, making it an essential part of armor systems.

        At present, bulletproof ceramic materials mainly include boron carbide (B4C), silicon carbide (SiC), and aluminum oxide (Al2O3), among which boron carbide is an important superhard material in nature with hardness second only to diamond and cubic boron nitride. It has the characteristics of high melting point, high modulus, small specific gravity, good self-lubricating, wear resistance, acid and alkali corrosion resistance, radiation resistance, neutron absorption, etc. It is a new type of high-performance engineering ceramic material with outstanding comprehensive performance. It has important applications in high-end bulletproof armor materials, high-end liquid and gas sealing materials, aerospace engine nozzles, high-end ceramic bearings, grinding media, polishing of hard materials, and precision grinding abrasives. In addition, boron carbide ceramics play an irreplaceable role in neutron absorption and shielding components of nuclear power reactors, and are an important national strategic material.

        Due to its lightest weight, high specific modulus, and good ballistic performance, boron carbide is considered a bulletproof ceramic material with excellent comprehensive performance. However, its preparation is not easy because the boron carbide structure is an extremely difficult to sinter ceramic material, with a covalent bond of 93.94%, much higher than other materials such as silicon carbide (88%) and silicon nitride (70%). Therefore, the elimination of pores, grain boundaries, and volume diffusion inside the boron carbide need to fully occur above 2200 ℃.

        In general, ordinary boron carbide powder can only achieve a relative density of 80% -87% when sintered without pressure at 2250-2300 ℃. Due to sintering under such high temperature conditions, the grains will rapidly coarsen and grow, which is not conducive to the elimination of pores and will generate a large number of residual pores, affecting the density of the material. At present, in order to improve the sintering density and performance of boron carbide ceramics, the hot pressing sintering method is more commonly used. However, the cost and price of this process are very expensive, resulting in limited application of hot pressing boron carbide. It is mainly concentrated in the high-end protection market, such as the protection systems of equipment such as helicopters, submarines, submarines, and fighter jets. With the continuous progress and innovation of technology in the future, it is believed that the performance and application fields of boron carbide materials will also be further expanded and improved.