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By utilizing the ultra-high hardness of B4C, various sandblasting nozzles can be made using it for the sandblasting heads of ship rust removal sandblasting machines, which has a lifespan several tens of times longer than using alumina sandblasting heads. The nozzle used for surface sandblasting treatment in aluminum products is also made of B4C, and its service life can reach more than one month. Generally speaking, superhard materials have good wear resistance, and B4C is also a good material for mechanical seal rings, which can be used for bearings, axles, high-pressure nozzles, etc.

During the research, it was found that the bulletproof mechanism of composite armor is that in the initial stage of projectile penetration, the penetration energy of the projectile is mainly borne by the ceramic panel. The ceramic dissipates energy through compression and shear damage, and the fiber backplate bulges and delaminates. The fiber deformation is not obvious, and the fiber elongation consumes energy.

Although traditional bulletproof ceramics have improved their bulletproof effect through certain toughening, they still have some drawbacks, such as increasing material toughness while sometimes reducing material strength. Moreover, traditional bulletproof ceramics are difficult to withstand continuous impacts, cannot be repaired after impact, are disposable, have high costs, low reliability, and do not have good structural designability.

At present, the main method for enhancing the toughness of boron carbide ceramics is to optimize the material composition, such as by increasing fiber/whisker toughening and second phase particle toughening. Second phase particle toughening is achieved by adding metal phases, transition metal borides, graphene, nanoparticles, rare earth compounds, etc., and changing the internal crystal structure of ceramics, such as controlling the microstructure of ceramics, reducing the particle size of grains, increasing the density of ceramics, and forming a layered structure of ceramics.

The research on enhancing the toughness and improving the density of silicon carbide ceramics has been our ongoing work. The main methods for enhancing the toughness of silicon carbide ceramics are to change the composition of the ceramic material, such as by increasing fiber/whisker toughening, second phase particle toughening, and changing the ceramic forming process to change the internal microstructure of the ceramic.

In the early days, armor plates were made of homogeneous armor, and most tanks and other armored vehicles were covered with steel plates. However, the density and weight of steel plate materials were high, and thick armor relatively reduced mobility. Therefore, in order to improve combat capabilities on the battlefield, after the end of World War II, specialized armor forms appeared by coating a layer of ceramic or depleted uranium on steel armor. Although the characteristics of ceramic materials were discovered early, their actual application for military purposes was not long.

1.Application of silicon carbide ceramic film in high-temperature flue gas purification Silicon carbide ceramic film has unique advantages in the field of high-temperature flue gas treatment due to its high temperature resistance, corrosion resistance, and thermal shock resistance. For particulate pollutants such as PM2.5, the dust removal mechanism of silicon carbide ceramic membrane is pore screening, interception, adsorption, etc. In addition, silicon carbide film has been widely used in high-temperature dust removal industries such as coal chemical, polycrystalline silicon, and steel.

Silicon carbide bulletproof ceramic Silicon carbide has extremely strong covalent bonds and maintains high strength even at high temperatures. This structural characteristic endows silicon carbide ceramics with excellent strength, high hardness, wear resistance, corrosion resistance, high thermal conductivity, and good thermal shock resistance; At the same time, silicon carbide ceramics have a moderate price and high cost-effectiveness, making them one of the most promising high-performance armor and protective materials.

In the military industry, pressureless sintered silicon carbide shines like a brilliant star. As a new type of material, it not only has advantages such as high hardness and thermal conductivity, but also can withstand high temperature and high pressure in extreme environments, making it an important component of military equipment. The emergence of pressureless sintered silicon carbide has brought new possibilities for the development of military technology, significantly enhancing the strategic advantages of military equipment. Its widespread application has injected new vitality into the military industry, elevating military strength to a new height.

Hot isostatic pressing sintering Hot isostatic pressing sintering of boron carbide involves placing powder compacts or encapsulated powders into high-pressure containers. Inert gases (such as N2 and Ar) can be used as pressure transfer media without the need for sintering aids, subjecting the powders to isotropic pressure and reducing sintering temperature. This results in the production of boron carbide ceramic materials with fine crystal microstructure, high bending strength, and density. Hot isostatic pressing sintering is a simple and low-cost preparation technology that can produce high-density, high-strength, and uniformly distributed grain products. This technology can achieve one-time molding of structurally complex products. The disadvantage is that the equipment investment is large and the equipment price is expensive.

Sintering is a crucial step in the preparation of B4C ceramics, and the main factors affecting the sintering of B4C ceramics include sintering method, particle size and activity of powder raw materials, type and dosage of additives, sintering temperature and insulation time, etc. At present, the sintering methods for boron carbide ceramic powder mainly include pressureless sintering, hot pressing sintering, hot isostatic pressing sintering, discharge plasma sintering, etc.Now let's talk about the advantages and disadvantages of pressureless sintering and hot pressing sintering.

Boron carbide has a history of nearly 170 years of development, and its atomic structure has been widely studied in recent years. Its main crystal structure is a 12 atom icosahedron and a three atom chain connected to the icosahedron. This structure is also known as a hexagonal structure, where carbon atoms and boron atoms can replace each other, resulting in boron carbide having many isomers.