At ISIS research is carried out using instrumentation designed specifically for engineering applications that can accommodate full-sized components, and allows users to map stresses in 3D. Modern aircraft engines use components made from high-performance alloys (which enhance both safety and fuel economy) that can be difficult to join together using conventional welding techniques. New techniques, such as linear friction welding, can introduce weaknesses into the joint. Research into the nature of the stresses involved allows both the optimisation of welding conditions, and the development of post-weld heat treatments to relieve the stresses. Airbus has used ISIS to research the integrity of welds in aluminium alloys, and to assess their suitability for future aircraft programmes.
ISIS’ neutrons can be used to see deep into the structure of engineering components such as aircraft wings. Through testing at ISIS, Airbus has been able to discover areas of potential stress and weakness in its aircraft parts, assuring the quality of engineering components before the manufacturing process. Neutron diffraction also enables measurement of stress fields in large aircraft wing test panels, providing information which leads to a better understanding of performance. This enables engineers to adjust the manufacturing process and make lighter and safer aircraft parts at a lower cost.
Cosmic ray chaos
The Earth is constantly being bombarded by cosmic rays, high-energy particles that come from our galaxy and beyond. Trillions arrive every second, most either deflected away by Earth’s magnetic field, or greatly slowed by our atmosphere. By the time they reach the surface of the Earth, the cosmic rays that are left pose no threat to health, but they can affect silicon chips and other electronic components.
The problem is 300 times greater at 30,000 to 35,000 feet – the altitudes at which jet aircraft routinely fly. A chip can be hit by a neutron every few seconds, and when a neutron hits silicon it can cause an electrical charge shower that can damage the chip or cause it to behave in an unexpected manner. As electronic components get smaller, the risk of damage increases.
Good design and testing are needed to compensate for the potential disruption. The ISIS neutron source can facilitate testing by supplying – in a very short timeframe – the same number of neutrons that a silicon chip might encounter during thousands of hours of flight. Manufacturers such as BAE, QinetiQ and MBDA are part of a consortium that use ISIS to test their electronic components, allowing them to build in triple redundancy and reduce the risk of damage to the electronics, in a timely and cost-effective manner.
To find out more about how science at STFC is making air travel safer, click here.
Research date: August 2015
STFC - ISIS