bulletproof ceramic materials types

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Ceramic materials possess many attractive properties, including high specific stiffness, high specific strength, and chemical inertness in many environments. At the same time, due to its low density, high hardness and high compressive strength relative to metal, its application in armor system is very attractive, and it has become a kind of protective armor widely used in bulletproof vest, vehicle, aircraft and other equipment.

Armor ceramic materials usually appear in the form of composite armor in practical application. It is widely used in the additional roof, hatchcover, exhaust plate, turret seat ring, bulletproof glass, pivot frame and other armored components as well as the underbody of tank vehicles; It is also used to manufacture torso panels, side panels, vehicle doors and driver’s seats. Among the main battle tanks, the current German Panther II, the British Challenger Series, the Israeli Merkava, the American Abrams (MI), eE-T1 Orsolio, and the Former Soviet T-72 have carbide ceramic composite armor on top, bottom, and sides.

The black Hawk is protected by boron carbide and Kevlar composite armor in the occupant seat. In 2016, bulletproof ceramic armor plate was added to the cockpit and shoulder sides of THE CAAC Wuzhi 10, which can resist the attack of 12.7mm large-caliber machine gun bullets, enhancing the self-protection ability of pilots.

Ceramic armor material should meet the requirements of “high hardness, high toughness, high strength, low cost and low density” as far as possible. Bulletproof armor materials began to diversify, compound, lightweight road, multi-channel to improve the protection level of armored vehicles to deal with higher level of threats.

At present, B4C, Al2O3, SiC, TiB2, AlN, Si3N4, Sialon and other special bulletproof ceramics are mainly used at home and abroad.

Alumina ceramics as ionic bond compounds, strong chemical bond, high melting point (2050°C) has good oxidation resistance and chemical inertia, sintered products surface clean, stable size, low price, so it is widely used in all kinds of armored vehicles and military police bulletproof clothing. However, Al2O3 has high density, low hardness and fracture toughness, so it has low elastic resistance.

Silicon carbide covalent bond is very strong, and it still has high strength bond at high temperature. This structure characteristic gives silicon carbide ceramics excellent strength, high hardness, wear resistance, corrosion resistance, high thermal conductivity, good thermal shock resistance and other properties. At the same time, silicon carbide ceramics with moderate price and high cost performance is one of the most potential development of high-performance armor protection materials. SiC ceramics has a broad development space in the field of armor protection, and its application tends to be diversified in the fields of individual soldier equipment and special vehicles. As a protective armor material, considering the cost and special application occasions, the ceramic panel arranged in small pieces is usually bonded with the composite material back plate to form a ceramic composite target plate, so as to overcome the failure of ceramics caused by tensile stress, and to ensure that only a single block is crushed without destroying the whole armor when the projectile penetrates.

Boron carbide is a strong covalent bond compound with a covalent bond as high as 93.9%. It has a high melting point and extraordinary hardness (35~45GPa), second only to diamond and cubic boron nitride. Especially, it has a constant high temperature hardness and good mechanical properties, making B4C one of the high temperature wear resistant materials with great development potential. B4C has the lowest density and the highest hardness among several commonly used armor ceramics, and its high elastic modulus makes it a good choice for military armor and space materials. Therefore, it is widely used in extremely strict quality requirements of the occasion, such as bulletproof inserts, military aircraft, armored vehicles, ships and so on. However, B4C’s main problems are its high price (about 10 times that of alumina) and high brittleness, which limits its wide application as a single-phase protective armor.

The transparent ceramics represented by AlON and MgAl2O4 have been applied in the field of armor protection, which can not only protect human body but also observe enemy situation at any time. Due to its high strength and hardness, transparent ceramics have become protective materials with development potential that can replace bulletproof glass, such as face shield, missile detection window, ground combat vehicle protection window, aircraft windshield and landing window, etc., mainly including single crystal alumina (sapphire), alumina nitrogen and magnesium aluminum spinel.

Although single-phase ceramics have some bullet-proof ability, the common problem is low fracture toughness and high brittleness. Therefore, the toughening of bulletproof ceramics has been a hot research direction. The strengthening and toughening methods mainly include composite ceramic system, functionally gradient ceramics, layered structure design and so on.

SiC-Al2O3, SiC- Si3N4-AL2O3, SiC-Si-Al2O3, SiC-Si3N4-Si-Al2O3, SiC- Si3N4-SI2O3 and SiC- Si3N4-Si2O3 composites, TiB2-TI functional gradient materials, TIB2-ALN composites, B4C-SIC composite ceramic materials.

As well as fiber-reinforced ceramic composites, the rapid and safe movement of personnel and equipment during the war provides a continuous demand for lightweight structural protection materials. The fibers used for toughening ceramics mainly include glass fiber and carbon fiber.

Modern warfare, guided by information technology, is developing towards the three-dimensional development of sea, land, air and sky. However, the head-on confrontation in local areas is also inevitable, and protective equipment can effectively guarantee the safety of personnel.

SIMUWU independent research and development of large hot pressing equipment, can meet the high standards of bulletproof ceramic insert board production requirements, casting military quality.