Can foam stop a bullet?

June 09, 2016

By David McNally, ARL Public Affairs

ABERDEEN PROVING GROUND, Md. (May 31, 2016) -- In a recent video making the rounds on the internet, a piece of armor is seen obliterating a speeding bullet.

The segment shows a bullet literally shattering when it impacts what is described as "composite metal foam."

For an in-depth look, we ask the experts in the U.S. Army Research Laboratory's Weapons and Materials Research Directorate.

"Composite Metal Foam technologies have been researched actively at the Army Research Laboratory since the early 2000s, primarily for blast and shock mitigation," said Matthew Burkins with the Armor Mechanisms Branch.

The posted video lacks detail with regard to target construction, target weight, projectile type and projectile velocity, Burkins said, but he noted that the researchers involved in the testing have published their findings.

In a paper, "Ballistic performance of composite metal foams," published in the journal Composite Structures, authors Drs. Matias Garcia-Avila, Marc Portanova and Afsaneh Rabiei, detail how composite metal foams absorbed approximately 60–70 percent of the total kinetic energy of the projectile.

"Composite metal foam is low-weight, high-strength metal foam manufactured using hollow metallic spheres embedded in a solid metal matrix," the paper states.

One of the authors, Portanova, is the Engineering Test Team leader from the U.S. Army Aviation and Missile Research, Development and Engineering Center's Aviation Applied Technology Directorate at Fort Eustis, Virginia.

The video report describes the armor system as containing a "boron carbide ceramic layer, a CMF layer and possible backing materials such as aluminum and Kevlar®."

"The densities are significantly higher than current state-of-the-art body armor systems," Burkins said. "Work continues with CMFs, as well as other technologies that can decrease weight and increase stiffness of backings in ceramic armor systems."

Another one of the paper authors, Rabiei, also teamed with ARL researcher Vincent Hammond in December 2012. This resulted in a separate study on the dynamic properties of CMFs.

As part of the ARL Sciences for Lethality-and-Protection Campaign, Army researchers are committed to the discovery, innovation and transition of protection systems that are "light weight, low burden, affordable and resilient towards a broad array of threats."

"The laboratory will continue to conduct research and monitor development of CMFs with an eye towards employing them wherever their unique properties will provide the warfighter with reduced weight and/or increased protection," he said.


The U.S. Army Research Laboratory is part of the U.S. Army Research, Development and Engineering Command, which has the mission to ensure decisive overmatch for unified land operations to empower the Army, the joint warfighter and our nation. RDECOM is a major subordinate command of the U.S. Army Materiel Command.

 

Last Update / Reviewed: June 9, 2016