Watch bulletproof FOAM turn gunshot to dust: Material can also block radiation and could lead to lightweight body armour
- New material called composite metal foam produces air filled steel plates
- Less than an inch is enough to stop an armour-piercing bullet from 16ft
- Tests showed it caused bullets to lose 65 per cent of their impact mass
- It could be used to create new lightweight body armour and to protect cars
By Richard Grey
8 April 2016
Foams are not typically known for their toughness and tend to be rather ethereal when touched.
But a new type of metal foam has been shown to be so strong it is capable of turning even armour-piercing bullets to dust.
The material, which is just a fraction of the weight of metal plating, could be used to create new types of lightweight body armour and protection for vehicles.
Known as composite metal foam, the material is made by embedding hollow steel spheres in a stainless steel matrix created from a metallic powder.
Tests of the foam showed that less than an inch of it was enough to stop armour-piercing rounds that would normally puncture other types of body armour.
In fact, the researchers behind the material found it actually caused the bullets to disintegrate upon impact.
Professor Afsaneh Rabiei, a mechanical engineer at North Carolina State University, said: 'We could stop the bullet at a total thickness of less than an inch, while the indentation on the back was less than eight millimetres (0.3 inches).
'To put that in context, the National Institute of Justice standard allows up to 44 millimetres (1.7 inches) indentation in the back of an armour.'
Using high speed cameras (video below), Professor Rabiei and her team were able to monitor what happened when they fired M80 and M2 armour piercing rounds at different types of armour from a distance of 16ft (5 metres).
The researchers found that combining the composite metal foam with a ceramic face plate, armour-piercing rounds fired at speeds of more than 1,900mph (3,057km/h), lost up to 65 per cent of their mass upon impact.