A bullet striking the surface of armor made from boron carbide ceramics causes it to lose its momentum and shatter into hard fragments. The ceramics then absorb the energy and dissipate it within the backplate of the armor.

Boron carbide is one of the world’s hardest manufactured materials. It has the molecular formula B4C and is typically gray-black in powder form. The material is used in body armor and vehicle and aircraft shields for its extreme hardness yet light weight.

The light weight of boron carbide armor is accomplished through a unique production process. Adept’s pressureless sintered boron carbide ceramics are made from highly abrasion resistant materials with a low porosity and extremely high hardness. This enables the creation of Level IV armor plates which are significantly lighter than conventional ceramic armor.

Scientists have long known that a jolt of a certain frequency can cause a phase transformation in boron carbide, changing the internal structure and presenting two or more physical states at the same time. The impact of a bullet transforms the atoms in boron carbide from a crystalline state in which they are systematically arranged to a glass-like state in which the atoms are haphazardly arranged. This weakens the integrity of the boron carbide at the point of contact with the bullet.

Prior research using computer simulations has suggested that adding small quantities of other elements could make boron carbide less brittle. Xie’s team experimentally verified this theory by making controllable dents in a boron carbide sample with a diamond tip and then observing the microscopic damage under a high-powered electron microscope. They found that when the samples were treated with silicon, the extent of the phase transformation was reduced by 30%. This significantly reduced the amount of indentation damage.