Jonathan Hughes

University Of Manchester

I am studying a PhD entitled “Microstructure Stability of Precipitation Hardened CuCrZr Alloys Under Irradiation” at the University of Manchester under the supervision of Dr Enrique Jimenez-Melero. Prior to joining the CDT I completed a Master’s Degree in Mechanical Engineering and Materials Science before working for 4 years teaching GCSE and A-level physics.

Copper has excellent heat transfer properties, thus making it the material of choice for any high heat flux component. Unfortunately copper suffers from low strength so often requires the addition of alloying elements in order to make it more structurally sound while retaining its heat transfer properties. My project revolves around the choice of CuCrZr alloys as a heat sink / structural element in the next generation of nuclear fusion reactors such as ITER. The high flux of high energy neutrons emitted from the fusion reaction can result in major microstructural changes through collision with the atomic structure displacing atoms, creating voids, redistributing alloying elements and causing clustering of lattice defects as well as material activation and transmutation. For now, the phenomena at micro / nano level responsible for the high temperature behaviour of the CuCrZr alloys under irradiation are not well understood, demonstrating an increased ductility, softening under irradiation at high temperatures with a pronounced transition to hardening and embrittlement under irradiation as the temperature drops below around 300oC.

My project aims to use proton beams to simulate neutron bombardment of these CuCrZr alloys and use SEM, TEM, EDS and EBSD techniques to examine the resulting changes in microstructure. This will be combined with mechanical testing in order to determine the link between changes in mechanical properties such as hardness and the changes that take place on a microstructural level under irradiation at different temperatures. The project also seeks to understand the role of Zr in the alloy by comparing CuCrZr alloys with CuCr alloys.