Engineering alloys, such as steels and tungsten alloys, are used extensively in extreme environments, including advanced fusion reactors and hydrogen storage housing. Deformation mechanisms of these materials need to be carefully studied for us to use them safely. This brought Dr Biao Cai and his team to ISIS to use Engin-x to test various materials.

“Engin-x has a lot of unique capacities, which allow us to apply stress to samples at extreme temperatures" says lead researcher Dr Cai. “Engin-x's neutron diffraction allows us to determine what is happening inside the material as we stretch it, which then inform us about how they could contribute to the strength of the material."

“The resolution of the detectors at Engin-x is also important for our experiments," added John​​, whose PhD is funded by EPSRC CDT in Topological Design and the UK Atomic Energy Authority. John is investigating tungsten alloys, as they are currently being researched as a potential heat sink component in fusion reactors. “In fusion reactors, there is enormously hot plasma that is similar to the temperature of the sun," explains John, “then you have super cooled superconducting magnets on the other side. It's like a transition between the extreme hot and cold temperatures. We study the properties of the materials such as tungsten alloys under such extreme temperatures at Engin-X, so that we can validate how they can be used in such environments."

In turn, Phoebe, whose PhD is funded by EPSRC CDT in Topological Design and the Manufacturing Technology Centre, is examining the properties of 316L stainless steels at very low temperatures. 316L stainless steel is a prospective material for hydrogen storage at cryogenic temperature. Although the mechanical performance of stainless steels at low temperatures has been well studied, the change in deformation mechanisms due to the hydrogen presence for 316L steel needs further investigation. “I'm comparing materials that have been exposed to hydrogen and seeing how steels could perform for cryogenic applications and how their structure and properties is affected."

Fusion is still in the research phase and industries plan to build fusion reactors to provide electricity. Dr Cai, John and Phoebe hope that neutron diffraction will uncover the controlling deformation mechanisms of engineering alloys for its use for fusion applications and as a housing material for hydrogen storage.