Mental Floss

A Metal Foam Material That Shatters Armor-Piercing Bullets on Impact

Andrew LaSane

"Armor-piercing" bullets could soon become a lot less effective, thanks to the work of researchers at North Carolina State University. According to Discovery News, the team developed a composite metal foam (CMF) that is both stronger and lighter than the metal currently used in protective plating for cars and body armor—and it causes armor-piercing bullets to explode on contact.

According to the research, led by a professor of mechanical and aerospace engineering, Afsaneh Rabiei, and published in Composite Structures, the scientists created the nearly 1-inch thick foam with a layer of boron carbide ceramic in front, CMF in the middle, and Kevlar backing. That composition allows the material to not only stop bullets, but to cause them to disintegrate on impact as well.

The slow-motion video above shows what happened when an M2 armor-piercing bullet was fired at the CMF. The material turned the bullet to dust and absorbed 60 to 70 percent of the ammunition's kinetic energy, the researchers pointed out.

It's an invention that could be used for more than just military armor. Rabiei's previous research proved that lightweight CMFs are also effective at shielding electromagnetic, gamma, and neutron radiation, and are twice as fire resistant as other metals because of air pockets in the material. According to the researchers, those features mean the CMF could eventually be used to for space exploration and nuclear waste transport technology.

[h/t Discovery News]