Metal foams capable of shielding radiation developed

Lightweight composite metal foams are effective at blocking X-rays, gamma rays and neutron radiation and are capable of absorbing the energy of high impact collisions, says a study.

The metal foams hold promise for use in nuclear safety, space exploration and medical technology applications.

"This work means there's an opportunity to use composite metal foam to develop safer systems for transporting nuclear waste, more efficient designs for spacecraft and nuclear structures, and new shielding for use in CT scanners," said Afsaneh Rabiei, professor of mechanical and aerospace engineering at North Carolina State University.

Rabiei first developed the strong, lightweight metal foam for use in transportation and military applications. But she wanted to know if the foam could be used for nuclear or space exploration applications.

For this, she and her colleagues conducted multiple tests to see how effective it was at blocking X-rays, gamma rays and neutron radiation.

The most effective composite metal foam against all three forms of radiation is called "high-Z steel-steel" and was made up largely of stainless steel, but incorporated a small amount of tungsten.

The foam also outperformed other materials at blocking neutron radiation.

"However, we are working to modify the composition of the metal foam to be even more effective than lead at blocking X-rays - and our early results are promising," said Rabiei in a study outlined in the journal Radiation Physics and Chemistry.

"The extraordinary mechanical and thermal properties of composite metal foams, and their energy absorption capabilities, make the material a good candidate for various nuclear structural applications," Rabiei added.