CMF armour cuts weight and adds protection

The latest advance in CMF materials from North Carolina State University (NC State) can stop ball and armour-piercing rounds whilst weighing less than half as much as conventional steel armour. Their findings are published in Composite Structures.

CMF is a foam that consists of hollow, metallic spheres - made of materials such as stainless steel or titanium - embedded in a metallic matrix made of steel, titanium, aluminium or other metallic alloys. In this study, the researchers used steel-steel CMF, so both the spheres and the matrix were made of steel.

For the study, researchers manufactured a hard armour system consisting of a ceramic faceplate, a CMF core and a thin aluminium back plate. The armour was tested using .50 calibre ball and armour-piercing rounds fired at impact velocities from 500m/s up to 885m/s.

According to NC State, the CMF layer of the armour was able to absorb 72-75 per cent of the kinetic energy of the ball rounds, and 68-78 per cent of the kinetic energy of the armour-piercing rounds.