Engineering

Neutron scattering has been used to determine how to best manufacture and weld piping materials for use in oil pipelines to reduce residual stresses and prevent cracking and oil leaks.

Neutron scattering has played an important role behind the scenes to protect public safety and the environment as technology forges ahead. Neutron scattering has guided improvements to ensure that trains don't veer off tracks, wings don't fall off airplanes, and pipelines don't corrode enough to leak oil. Such failures are often caused by internal stresses, which develop in a part during the manufacturing process and can predispose materials to cracking, wear, accelerated chemical attack, and even failure brought on by externally imposed stresses. Engineers want to know when failure is likely to occur in a part and whether use of different materials and manufacturing processes would produce a part that will last longer. Neutron-scattering results—combined with computer models— can provide these answers.

The Corbin Bridge in Pennsylvania was the first to have an aluminum deck replacement (in 1996). Aluminum welds for such decks are being characterized by neutron scattering.

The aluminum industry is interested in building aluminum bridge decks that are as strong and corrosion resistant as steel decks. Because aluminum decks are lighter than steel ones, less costly support structures could be built. Also, the modular construction of aluminum decks will make it easy to replace bridge parts. Scientists have developed ways to use neutrons to study residual stresses in aluminum welds in aluminum bridge decks.

SNS research will allow engineers to measure subtle structural details in small samples or in huge engineering samples, such as earth-moving equipment. Such research will enable effective measurements of residual stresses in composites—which are being used increasingly to make cutting tools, aircraft structures, and engine parts—because they are stronger and lighter than other materials.

To build a large engineering marvel such as a safe, efficient turbine jet engine, it helps to understand how metallic alloys in turbine blades behave under extreme stress at a microscopic level. Engineers think big, but the success of their projects often depends on insights into the small provided by neutrons.