Nano-scale X-ray vision offers new insight

New research by Trinity Lecturer in Engineering Felix Hofmann reports a step change in the ability to characterise the crystal defects that control the behaviour of most metals and alloys. His team’s use of X-ray microscopy allowed nanoscale examination of material defects and the distortions they cause. The result, published in the journal  Physical Review Materials, promise new insights for the optimisation of high performance materials for aerospace and power generation.

Atoms in most metals and alloys are arranged in a regular pattern. Imperfections in this crystal structure have a dramatic effect on the properties of the material. The new research, carried out in collaboration with colleagues at the Advanced Photon Source in the US, uses an X-ray diffraction technique called Bragg Coherent Diffraction Imaging (BCDI) to identify and measure the impact of material defects. BCDI requires very small samples, and until recently could only be used on materials that naturally form suitably small particles; unfortunately, almost none of the most important engineering materials fall into this category.

Professor Hofmann’s team developed a new approach allowing the investigation of defects in important engineering materials such as tungsten – the most promising material for armour components in future nuclear fusion rectors. In service, tungsten armour will be exposed to intense heat and radiation levels for tens of years. This extreme environment causes defects within the metal, and it’s vital for engineers to understand how those defects might impact the material’s strength – particularly in the event of an accident.

Professor Hofmann explains: ‘Detailed knowledge of the structure of crystal defects is essential for optimising material performance. Normally you think of defects as being bad, however there is a fantastic opportunity here to enhance material properties by defect engineering.

‘We’re very excited to publish this ground-breaking research. It’s the culmination of a nine year ambition, and a lot of work has gone into it. This technique has the potential to change our understanding of the advanced alloys used in industries such as aerospace and nuclear power. We really want to get it out there as an enabling tool for the research community.’

Posted: 21 January 2020

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