Thermo-Mechanical Modelling for Structural Ceramics with Johnson Matthey

Fatigue fracture is one of the failure modes in engineering ceramics where crack initiates, propagates, and finally results in failure under cyclic thermal loading. The efficient prediction of fatigue crack growth helps make engineering decisions on product durability. The conventional Paris law or J-integrals are not enough to predict crack growth in complex 3D geometries such as 3D perioidic structures from additive layer manufacturing. As an alternative method, the Phase Field models have been receiving increasing attention. In this approach it is possible to model both plastic and elastic deformations with a time in microcracked ceramics. The model predictions can also be used to track weaker zones in the structure and the severity of the applied loading conditions on the product durability. There is a knowledge gap in extending the Phase Fieldd models for elasto-plastic ceramics and measuring model input parameters such as fracture toughness, separation energy, cohesive strength, fatigue parameters for such complex structures such as honeycombs. In this work,
Phase Field models will be developed to understand the durability of the microcracked systems and novel experimental techniques will be developed for measuring model parameters by utilizing facilities like high temperature bending test, Dynamic Mechanical Analyser, high-temperature impulse excitation, and nanoindentation. The model predictions will be validated on model materials under thermal shock load conditions. Similarly, these models will be used to explain the revesible grain growth and hysteresis in the elastic properties of microcracked ceramics.
This project will specifically address some of the product development and quality control needs of JM. The EngD student will work as an integral part of thermal processing group and quality control teams. JM is building an enhanced capability in this area, enabling the model driven manufacturing & design. The EngD researcher will play a key role within this team; developing bespoke measurement methods, fracture model for a given product formulations. The focus of the EngD will be the fundamental R&D needs of the group, but also being involved in trials and implementation of models in commercial environment and support different manufacturing sites in Europe . For any concern with Brexit, this position is fully paid and sponsored.