Boron carbide ceramics is a new type of non-oxide ceramic material with a high melting point, high hardness, large neutron capture surface, low density, good chemical inertness, excellent thermal and electrical properties, etc. Boron carbide, also known as black diamond, is the third hardest material after adamantite and cubic boron nitride. In addition to being used in large quantities as an abrasive, boron carbide is also used in the production of various wear-resistant components, thermocouple elements, high-temperature semiconductors, thermoelectric conversion devices on spacecraft, bullet-proof armour, reactor control rods and shielding materials.Although expensive, boron carbide ceramics is still the preferred choice for armour systems where weight reduction is a priority, given its superior performance and the fact that it has the highest protection factor of 13-14.
Boron carbide ceramics in ballistic protection
The technological level of ballistic protection materials is also an important reflection of a country’s military strength. Boron carbide have been widely used in bullet-proof vests, bullet-proof armour, armed helicopters, as well as in police and civilian special vehicles. Compared to other ballistic materials such as sheet metal ballistic materials, high-performance fibre composite ballistic materials and combined ballistic materials, boron carbide ceramics have become the ideal alternative for ballistic materials due to their high melting point, high hardness and low density.
1.1 Bulletproof armour
Ballistic ceramics were first used in China in the field of ballistic armour. At present, aluminium oxide, boron carbide, silicon carbide, aluminium nitride, titanium boride and silicon nitride are the main materials used for armour protection at home and abroad. There are three main types of single-phase ceramics used for armour protection: alumina, boron carbide and silicon carbide. Armour ceramics are mainly used in bullet-proof armoured vehicles and are often found in the form of composite armour. Armour ceramic materials are commonly used in armour components such as additional roofs, hatches, exhaust panels, turret seats, bulletproof glass, pivot frames and the lower hull of tank vehicles, as well as in the manufacture of torso plates, side panels, vehicle doors and driver’s seats. In main battle tanks, the German Leopard-II, British Challenger series, American Abrams (Ml), EE-T1 Osorio, Israeli Merkava, Soviet T-72 and other main battle tanks are currently fitted with carbide ceramic composite armour on their top, bottom and all sides. In recent years ballistic armour materials have begun to diversify, compound and become lighter.
1.2 Armed helicopters
Boron carbide ceramics are particularly suitable for use in helicopter gunships and other aircraft, and can be used to protect against ground-based shelling by improving traditional designs. For example, boron carbide and Kevlar composite armour has been widely used in the crew seats of American Blackhawk helicopters; in the 1960s, boron carbide ceramics were fitted to the cockpit floor, side wall panels and pilot’s seat of helicopter gunships. This enhances the pilot’s ability to protect himself.
1.3 Police and civilian special vehicles
Boron carbide are an excellent material for stopping low-energy projectiles and are widely used in special vehicles for police and civilian applications. Special vehicles not only require all-round protection, but also require that the operator’s view is not obstructed. Boron carbide ceramics are replacing traditional armoured steel plates in the floor, doors, toolboxes, seats and other important parts of special vehicles, making them a new bullet-proof material for the conversion of police and civilian special vehicles. Commercial premium cars such as Red Flag, Ford and Toyota; special vehicles such as money transport vehicles, escort vehicles, VIP vehicles and anti-riot vehicles have all made successful attempts to apply boron carbide ceramic armour.
1.4 Bulletproof vest
The first boron carbide for personal protection, the Interceptor, was developed in the early 1960s for the US Marine Corps and Army. By 2012, 68,000 Interceptor vests had been put into service. The US and Israel have also produced vests with ceramic boron carbide chips embedded in Kevlar fabric. The US Army laboratory has produced B4C ballistic helmets using a hot isostatic sintering process. In China, the military industry has worked hard to improve and produce boron carbide ceramic body armour that is high performance, light weight and relatively comfortable.