Super-resolution 3D ultrasound tomography for material microstructure characterisation

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Active

EPSRC
EPSRC
EPSRC
EPSRC
EPSRC

No funds listed.

Jan. 1, 2023

Dec. 31, 2026

Ultrasonic tomography is a powerful non-invasive tool widely use in medical diagnostics as well as non-destructive testing. Conventional tomographic methods represent a model-based sound velocity reconstruction of a medium, which assigns every voxel a sound velocity representing local material properties. This type of signal processing can be performed, for example, using elastic guided wave measurements for a wall thickness mapping in pipes and plate-like structures, or for the human brain imaging inside the skull. Ultrasonic tomography, however, has substantial untapped potential for multispectral, aspect-dependent, and area-specific imaging.

Non-destructive volumetric material characterisation is an important problem with a wide range of applications in many areas. For example, the knowledge of material microstructural parameters is crucial for accurately estimating the lifetime of safety critical components in aerospace (jet engines and landing gears) or energy sectors (nuclear power plants). Detailed microstructural examination of metallic components can be performed using several established characterisation methods, such as optical microscopy, X-ray, Electron Back-Scattered diffraction (EBSD). However, all these methods are restricted to surface or near surface inspections. Moreover, some techniques are essentially destructive (EBSD), require complex surface preparation and are limited to relatively small inspection regions. Therefore, there is a clear need for additional methods capable of quantifying material microstructure in large sample volumes. It is also critical that such techniques significantly reduce both the time and surface quality requirements compared to conventional methods such as optical microscopy and EBSD.

This project is driven by the recent advances in defect characterisation using ultrasonic arrays, which are based on the analysis of backscatter patterns of small subwavelength targets. The main aim is to expand ultrasonic tomography functionality fundamentally to create an efficient tool to produce a quantitative map of microstructural parameters of metals corresponding to each local material region. This requires a fundamentally different and innovative imaging concept.

The measurement set-up will be implemented in a robotic arm scanning system, which will allow to perform ultrasonic transmitter-receiver measurements for a wide range of incident and scattered angles. The imaging approach exploits time-reversal properties of sound wave propagation and is based on reversible forward- and back-propagation imaging operations.

Potential Impact:
The proposed CDT in NDE will deliver impact (Industrial, Individual and Societal) by progressing research, delivering commercial benefit and training highly employable doctoral-level recruits able to work across industry sectors.

Industry will benefit from this CDT resulting in competitive advantage to the industrial partners where our graduates will be placed and ultimately employed. The global NDE market itself has a value of USD15 billion p.a. [Markets and Markets NDE report January 2017] and is growing at 8% per year. Our partners include 49 companies, such as Airbus, Rolls-Royce, EDF, BAE Systems, SKF and Shell, whose ability to compete relies on NDE research. They will benefit through a doctoral-level workforce that can drive forward industrial challenges such as increased efficiency, safer operation, fewer interruptions to production, reduced wastage, and the ability to support new engineering developments. Our 35 supply chain partners who, for example, manufacture instrumentation or provide testing services and are keen to support the proposed CDT will benefit through graduates with skills that enable them to develop innovative new sensing and imaging techniques and instrumentation. To achieve this impact, all CDT research projects will be co-created with industry with an impact plan built-in to the project. Our EngD students will spend a significant amount of their time working in industry and our PhDs will be encouraged to take up shorter secondments. This exposure of our students to industry will lead to more rapid understanding, for both parties, of the barriers involved in making impact so that plans can be formulated to overcome these.

Individual impact will be significant for the cohorts of students. They will be trained in an extremely relevant knowledge-based field which has a significant demand for new highly skilled doctoral employees. These graduates will rejuvenate an ageing workforce as well as filling the doctoral skills and capability gaps identified by industry during the creation of this CDT. Our industrial partners will be involved in training delivery, e.g. entrepreneurial training to equip our graduates with the skills needed to translate new research into marketed products. Many of the partners are existing collaborators, who have been engaged regularly through the UK Research Centre in NDE (RCNDE), an industry-university collaboration. This has enabled the development of a 5,10 & 20 year vision for research needs across a range of market sectors and the CDT training will focus on these new priorities. Over the duration of the CDT we will actively discuss these priorities with our industry partners to ensure that they are still relevant. This impact will be achieved by a combination co-creation and collaboration on research projects, substantive industrial placements and as well as communication and engagement activities between academic partners and industry. Events aimed at fostering collaboration include an Annual CDT conference, technology transfer workshops, networking events as well as university visits by industrialists and vice versa, forming a close bond between research training and industrial impact. This approach will create lasting impact and ensure that the benefits to students, industry and society are maximised.

Society will benefit from this CDT through the research performed by our CDT graduates that will underpin safety and reliability across a wide range of industries, e.g. aerospace, energy, nuclear, automotive, defence and renewables. As NDE is an underpinning technology it feeds into many of the UK Government's Industrial Strategy Challenge Fund Grand Challenges, for example in energy, robotics, manufacturing and space. It is aligned to the EPSRC prosperity outcomes, e.g. the Productive Nation outcome requires NDE during manufacture to ensure quality and the Resilient Nation requires NDE to ensure reliable infrastructure and energy supplies.