The project will develop high performance permanent magnet materials based on Nd-Fe-B materials for automotive applications. This research will be guided by computer modelling being performed by another PhD student project. This will include the use of coatings, graded materials and investigation of novel microstructures and grain designs.
Thin films will be deposited using a new multi-technique deposition system to develop new materials and microstructures. Novel powders will be fabricated using new powder processing facilities at the Department's Royce Translational Centre (including gas atomisation, powder milling and plasma spheroidisation) and create bulk specimens using spark plasma sintering (SPS) and vacuum sintering with aligned powder grains.
We will use a new SQUID/VSM magnetometer (HRI funded; 7T magnetic field) to measure temperature-dependent magnetic properties. Crystal structure, microstructure and element distributions will be characterised using electron microscopy techniques (SEM, EDX, EBSD), glow discharge optical emission spectroscopy, X-ray diffraction and X-ray tomography; the latter will include central facilities beamtime applications to simultaneously characterise grain positions and orientations.
The modelling that will guide this project will use finite element and finite difference micromagnetic packages with advanced microstructural generation to simulate magnetic properties. It will explore the effects of grain size, shape and boundaries, and compositional variation, secondary phases, diffusion effects and porosity. Finally, it will use micromagnetic simulation outcomes to inform large-scale FEM simulations for bulk property predictions. Materials properties established through the experimental programme will be fed back into the models.
The project is supported by VW and will involve a three-month placement at their Research Centre in Wolfsburg, Germany.