Micro-scale modelling of thermo-mechanical and environmental degradation of non-oxide Ceramic Matrix Composites (CMC)

This project focuses on understanding how non-oxide ceramic matrix composites (CMC) perform under extreme environmental conditions, particularly silicon carbide (SiC) fibres with boron nitride (BN) interphases embedded in SiC matrices. Such materials can not only operate continuously at high temperatures (up to 1400 degrees Celsius) without the need for active cooling, but also are considerably lighter than their metallic counterparts and, as such, are increasingly replacing nickel superalloys in hot sections of gas turbines and aero-engines.

This research aims to investigate the microscale degradation mechanisms of CMCs when subjected to thermo-mechanical loading coupled with environmental oxidation. Microscale Finite Element (FE) models accounting for thermo-mechanical degradation as well as oxidation reactions will be developed to replace current empirical and semi-analytical analysis tools which are currently the state-of-the art in industries such as aerospace and power generation. These will then be verified and validated against experimental data on single tows (i.e. 'minicomposites') before being applied to meso-scale models of the 2D and/or 3D woven CMC laminates used in the manufacture of real components.

The potential impact of this research is significant. By improving the understanding of the thermo-mechanical and oxidative behaviour of the various phases within the material, this work will contribute to the development of safer, more efficient, and more durable components for a variety of high-temperature applications. Replacement of metals with CMCs in aero-engines can reduce weight and improve fuel efficiency, contributing to lower emissions and reduced operating costs. Beyond aerospace, this work will provide a step-change in the ability to design CMC components for various industries, including nuclear fission/fusion and gas turbines for power generation.

This project bridges various aspects of physical sciences and engineering by combining knowledge of thermo-mechanical and oxidative behaviour of advanced CMCs with the design and manufacture of components for high-temperature applications, with potential for great technological advancements in key sectors such as aerospace and power generation.