Project title: Understanding and Predicting Properties of MAX Phases.

Supervisor: Professor Mike Finnis

Project description:
MAX phases are a category of materials known for their excellent stability at high temperatures. This fact has led to a growing interest in them for many industrial applications [1]. Of special interest are the Zr-based MAX phases and in particular, a recently synthesized phase, Zr2AlC, due to their potential to be applied in nuclear energy production as fuel cladding, where the operating environment necessitates novel materials that can withstand high temperatures, oxidizing coolants, and rapid neutron fluences. However, little is currently known about the stability of such phases. Specifically, Zr2AlC was only recently synthesized, there is limited experimental research available and the published theoretical research has mostly focused on zero-temperature conditions. This has led to a lack of essential information about the stability of this compound which is critical for understanding its synthesis and its reliability as a structural material in its intended applications.

 This research aims to provide an improved understanding of MAX phases, with a focus on Zr2AlC, by applying tools such as density functional theory (DFT). DFT is combined with new advanced sampling techniques to calculate free energies at high temperatures, up to the melting point [2], including the effect of point defects. The materials’ thermophysical properties will then be predicted.

[1] Barsoum MW, Radovic M. Elastic and Mechanical Properties of the MAX Phases. In: Clarke D.R., Fratzl P., editors. Annual Review of Materials Research, 41, 195 (2011).

[2] Duff AI, Davey T, Korbmacher D, Glensk A, Grabowski B, Neugebauer J, Finnis MW, Improved method of calculating ab initio high-temperature thermodynamic properties with application to ZrC, Phys. Rev. B 91, 214311 (2015).