NEW DEVELOPMENTS

Unusual impact-resistant material combinations for safety equipment and other applications

Penn State engineer Dr. B.L. Lee shows that some unusual pairings of dissimilar materials have significantly enhanced impact penetration resistance when they are only lightly attached together -- offering new options for safety equipment and other applications.

For example, a "sandwich" composed of a plate of carbon/graphite fiber-embedded epoxy resin, a stiff, lightweight, easily-penetrated composite material, lightly attached to a thin backing sheet of resin-coated new Kevlar KM2 fabric, a composite highly impervious to ballistics, has double the penetration resistance of the tightly bonded materials. A sheet of armor grade composite material loosely bonded with ceramic face tile has four times the penetration resistance of the armor grade material alone while conventional bonding increases the resistance to penetration only three fold.

"The reason that weaker adhesive, such as spot-bonding, works better than normal lamination with strong adhesive, is the same reason that a Bible in a shirt pocket sometimes protects soldiers in battle from bullets and shrapnel. The air layers between the Bible's pages or between the sheets of carbon/graphite epoxy and Kevlar act to slow the entering projectile down," notes Dr. Lee.

The unusual pairings of materials he and his research group have identified offer potential for lighter, stronger and less penetrable safety helmets, airplane structure panels, automobile bodies, electronic equipment shielding panels, and military personnel armor.

For more information contact Penn State University, Dr. Lee, 814-865-9481.

Pulsed neutron linear accelerator

Los Alamos National Laboratory will build a half-mile-long linear accelerator for the Spallation Neuron Source, a $1.3 billion facility that will produce the most intense pulsed neutron beam in the world.

Spallation is a term used to describe the reaction that occurs when a high-energy particle bombards an atomic nucleus, ejecting some of its neutrons. When aimed at a sample, some of these neutrons will interact with the nuclei and bounce away at an angle. This phenomenon, called neutron scattering, can provide detailed information that cannot be learned in any other way about the structure, motion and atomic interactions of a wide range of materials.

Neutron scattering research has already been valuable in the development of such products as small electric motors, plastics, lubricants, jet aircraft and high-temperature superconductors, and the DOE has made construction of a new neutron-scattering facility a high priority.

For more information, contact Los Alamos National Laboratory, Los Alamos, NM,
505-665-9197.