University of Nottingham: Harnessing ultrasonic imaging to revolutionise manufacturing processes

A £1.4m pioneering project examining how ultrasonic imaging can be delivered remotely aims to revolutionise the quality of manufacturing processes.

The three-year project, funded by the Engineering and Physical Sciences Research Council (EPSRC) is aiming to develop a new capability for real-time, remote ultrasonic imaging that can be used for non-destructive evaluation in industry.

The research team, led by the University of Strathclyde and involving the Universities of Nottingham and Bristol, will examine how Laser Induced Phased Arrays (LIPAs), based on principles of laser ultrasonics, can be used to cut the imaging process in manufacturing from half an hour to under a second.

The remote arrays, made of light, can be applied in extreme environments, such as in process monitoring or inspection, and will be designed to pick up potential issues to enable the process be stopped or modified if faults are detected. As well as controlling the manufacturing process itself, it could mean the material could be reworked or improved.

Project lead, Dr Theodosia Stratoudaki from Strathclyde’s Centre for Ultrasonic Engineering, said: “The long-term vision behind this project goes beyond inspection, to develop a method for monitoring and control of in-process parameters, in places of extreme environments such as fusion reactors or turbine engines.

“An array has more than one element inside, but up until now it’s had a fixed geometry – like when you are taking a medical scan, you have an instrument which you place and then take a scan.

“What we are proposing is to break that concept completely and instead of the fixed geometry of instrumentation, the array will actually build as it is scanning by taking feedback from whatever is it imaging, so it is being reconfigured according to what the image is inside.

“It saves time and data and by the end of the project we are aiming to have a system that will be able to take ultrasonic images in under a second without having any contact.”

The array could be used in places with extreme temperatures or restricted access such as the inside of a turbine engine, as light can reach through confined spaces. It could also be used in space, and other places where contamination is an issue or radioactive atmospheres.

Professor Matt Clark, head of the University of Nottingham’s Optics and Photonics Research Group, explained their contribution to the project as improving the speed at which information is collected from the parts being inspected.

“This is done by increasing the number of points at which the signals are generated by the use of laser patterns projected onto the part or by the use of an array of laser diodes. This combined with parallel signal detection will allow us to drastically reduce the signal acquisition time. “These speed improvements bring the inspection time in line with the manufacturing time for metal 3D printing. The real-time inspection of the complex components made using metal 3D printing would help spot and repair any defects that occur, alongside minimising the need for costly post-manufacture inspections.”
Professor Matt Clark
Dr Stratoudaki added: “If you have a means of looking inside the material as its being made, then you can feed that information into the process and change it so that it makes what you want it to.

“An example is with additive manufacturing – metal 3D printing – which is making shapes. Making material that is stiffer in one place and more flexible in others isn’t possible at the moment, but if you have a means to control the whole thing as it’s being built, then the material could be tailor made and more complex structures could be made.

“Making one larger component instead of several also prevents failures in the joins and reduces the possibility of defects, obviously of huge importance in sectors like aerospace, the nuclear industry and other safety critical applications.”

EPSRC is the main funding body for engineering and physical sciences research in the UK and is part of UK Research and Innovation. The project partners also include BAE Systems, Sellafield Ltd, Hitachi and The UK Atomic Energy Authority. This project is a Targeted Research Project of the UK Research Centre in Non Destructive Evaluation.