ARCANE Doctoral Projects

Rolls-Royce plc and the University of Birmingham have developed some understandings/insights and capabilities in another funded project, which offers a foundation for a novel PhD project to develop a modelling capability to optimise the design of additive manufactured filters as counter-measures to the formation of oxide stringers in the liquid metal. The PhD candidate, who will study at the University of Birmingham and the University and Rolls-Royce's joint High Temperature Research Centre, will consider liquid metal filtration methods, cleanliness & flow related casting defects, of high performance superalloy investment castings. This will include; measuring filter effectiveness for oxide removal, CFD modelling of mould flow optimisation, particle capture methods, and issues surrounding the optimisation of filter design.

Liquid metal filtration and cleanliness for high performance superalloys at University of Birmingham on FindAPhD.com

Heterogeneous nucleation occurs within Ni-base superalloys in the presence of impurity sites on the surface of a ceramic shell during investment casting. Different chemical element impurities have differing catalysing effects on the heterogeneous nucleation. The PhD candidate, based at the University of Birmingham and the high temperature research centre (HTRC), would undertake heterogeneous nucleation casting experiments, by controlling differing elemental impurities. A full microstructural characterisation of the heterogeneous nucleation can allow for fundamental thermodynamic understanding to be developed for different impurities within an industrially used Ni-superalloy investment casting.

Fundamental studies of heterogeneous nucleation at University of Birmingham on FindAPhD.com

A computational modelling PhD project with the University of Birmingham, researching multi-component dendritic growth during directionally solidified casting of Ni-base superalloys. The project will include; Phase field simulations and code development, consideration of interfacial properties through molecular dynamics (MD) methods, development of dendritic growth current understanding, binarisation techniques, prediction of DSC traces, and simulation of texture development. Experimental validation approaches will also be developed.

Modelling of multi component dendritic growth at University of Birmingham on FindAPhD.com

Alloys solidify as dendrites forming crystalline microstructures which play a key role in determining the performance and overall material properties of components. However, defects during solidification can significantly degrade these properties, leading to failure. One phenomenon that is not well understood is the deformation of dendrites during solidification, despite being considered a key factor in the formation of many defects. This PhD study aims to investigate how external forces (e.g. electromagnetic, hydrodynamic, ultrasonic, gravitational) influence deformation of dendrites concurrently with solidification. The PhD, based at the University of Greenwich, will primarily be computational, utilising state-of-the-art numerical techniques and high-performance computing to predict deformation behaviour.

Computational modelling methods for manufacturing processes, such as those using the Finite Element (FE) method rely upon accurate descriptive behaviour of plasticity during deformation. In a polycrystalline structure, the random grain orientation largely makes material response isotropic. However, for SX castings, the highly anisotropic response due to the crystal orientation is critical. To improve the accuracy and reliability of modelling, crystal plasticity methods can be implemented to allow for full predictive capability of plastic deformation across different planar orientations based upon the fundamental crystallographic structure of Ni-base superalloy. Thus, this PhD, based at the University of Birmingham, will aim to develop a framework for Crystal plasticity computational modelling for nickel-based superalloys with an industrial application.

Crystal Plasticity (CP) Modelling in Single Crystal (SX) Superalloys at University of Birmingham on FindAPhD.com

Aerospace and aeroengine manufacturers have utilised single crystal (SX) casting technologies for manufacturing critical components, given the performance in strength that a single crystal casting possesses, compared to polycrystalline material. Defects within a SX casting will cause a loss of mechanical performance. This PhD, based at the University of Birmingham, will assess the impact in the mechanical properties for a high performance SX superalloy, based upon defect type, size, location. This PhD will require the student to undertake, (i) High fidelity mechanical testing of SX superalloys with and without defects present, (ii) Microstructure characterisation of Ni-base SX superalloys, and defects within the SX casting.

Role of Defects on Mechanical Behaviour of Single Crystal Superalloys at University of Birmingham on FindAPhD.com

Within a SX superalloy casting, the material experiences a highly anisotropic response to mechanical loading, caused by the crystallographic orientation and preferential slip-systems. A phenomena called strain banding sees highly localised deformation occurring, often in thin planar bands though the material. This PhD, based at the University of Birmingham, intends to investigate localised strain banding effects as they occur within several commercially applied SX superalloys, through numerous experimental techniques such as scanning and transmission electron microscopy, mechanical testing and materials modelling methods.

Strain-banding in Single Crystal (SX) Superalloys at University of Birmingham on FindAPhD.com

Comprehensive elasto-viscoplastic models for Ni-base superalloys - for industrial casting modelling applications

A ‘Comprehensive’ material model requires data across a wide range of operating temperatures (from room temperature up to pouring temperature) and at appropriate cooling rates seen in SX casting. For industrial application, developed elastic-viscoplastic materials models should be implemented via ProCAST User Functions by the PhD candidate, in advance of ESI potentially developing built-in support. The PhD project, based at Rolls-Royce and the University of Birmingham's joint High Temperature Research Centre (HTRC) will involve experimental measurements of high temperature behaviour. The desired end-product of the PhD project is industrial application (runtime and resource restrictions) for prediction of conditions likely to cause RX during heat treatment. Quantification of errors associated with implementation in an industrial setting would be highly valued.

Comprehensive elasto-viscoplastic models for Ni-base superalloys - for industrial casting modelling applications at University of Birmingham on FindAPhD.com

Dynamic responses of solidification microstructure to geometry-induced changes in casting conditions

Solidification conditions experienced in industrially relevant SX component castings are often far from the uniform, constant conditions generally published in the academic literature. There is a need to examine dynamic responses to changes in conditions, which are often caused by changes in geometry, caused by complex features. How fast do microstructures respond to changes in conditions? Do they change smoothly, or more abruptly once activation thresholds are exceeded? How can such mechanisms be described and simulated numerically, leading to industrial application? The PhD candidate will be based at Rolls-Royce and the University of Birmingham's joint High Temperature Research Centre (HTRC).

Dynamic responses of solidification microstructure to geometry-induced changes in casting conditions at University of Birmingham on FindAPhD.com