Developing MAX phase coatings for nuclear fusion – Materials Strand Project

Supervisor/s: Dr Philipp Frankel, Prof Sarah Haigh (University of Manchester).

External Supervisor/s: Dr Max Rigby-Bell (UKAEA)

Background

MAX phases possess an extensive chemical and structural diversity which results in a wide range of thermal, mechanical, corrosion and irradiation-related properties, depending on the composition and structural configuration.

The discovery and characterisation of low activation, radiation-hard MAX phases with promising mechanical properties would represent an important step in developing suitable plasma facing component armour for future fusion energy devices.

Recently, new MAX phase ceramics in the (Ta,Ti)3(Al,Si)C2 system were designed, synthesised and characterised using ‘low activation’ elements where possible, for potential use in future nuclear fusion applications. Thermal analysis and proton irradiation trials of (Ta,Ti)3AlC2 phases produced promising results in relation to the materials’ expected response to fusion-relevant environments.

However, the effect of replacing Al with increasing amounts of Si and/or Ga (i.e. low activation elements) on the materials’ response to irradiation has not been fully investigated. Equally, the materials’ mechanical properties have yet to be investigated.

Synthesis and proton irradiations of various (Ta,Ti)3(Al,Si)C2 phases have been performed, but the irradiated materials have not been characterised. Additionally, (Ta,Ti)3GaC2 synthesis trials are ongoing at TAU in Israel, through a collaboration with Asst. Prof. Maxim Sokol. If successful, this will represent the discovery of a new, low activation, MAX phase.

Proposed work

Using a combination of proton irradiations performed at the University of Manchester’s Dalton Cumbrian Facility, and a suite of powerful materials characterisation techniques including X-ray diffraction, high-resolution electron microscopy and various mechanical property measurement tools, the student will investigate the response of MAX phases to simulated nuclear fusion environments. The results of these experiments, along with the optimisation of bulk material attributes such as composition, phase purity and microstructure, will guide the development of radiation-hard MAX phase coatings for future nuclear fusion applications.

Project will be mainly based in Manchester but will be expected to visit UKAEA (Harwell) and Manchester University’s Dalton Cumbria Facility to perform experiments. Previous student completing an earlier project in the group benefited hugely from an extended visit to experts in the USA where new MAX phase compositions were synthesised and a similar visit could be beneficial here to synthesis new compositions, depending on the interest of the student.

This project is offered by the University of Manchester. For further information please contact Max Rigby-Bell max.rigby-bell@ukaea.uk , Philipp Frankel philipp.frankel@manchester.ac.uk  or Sarah Haigh sarah.haigh@manchester.ac.uk

This project may be compatible with part time study, please contact the project supervisors if you are interested in exploring this.

Figure 1 above: Atomic resolution STEM micrograph of a Ta-based MAX phase.