This project proposes to investigate the way the polymeric powders of different shapes and sizes flow, interact and sinter in the Laser Sintering process, through modelling and experimental validation. Laser sintering is part of the additive manufacturing technology, known for its benefits in industries where custom made products, lightweight and complex designs are required. In laser sintering a polymer powder bed is heated to just below its melt temperature. A laser is then focused onto the bed which scans a raster pattern of a single layer of the final part. The bed lowers slightly and a new layer of powder is applied. The process is then repeated until the component is made and the additive layer process is complete. The spreading and compaction of the powder is an important part of the LS process, a non-uniform layer of powder leads to high porosity and weaker bonding between layers and therefore a structure with poor mechanical performance. Similarly, the size and shape of particles can change the sintering process. Larger contact areas between particles lead to a good sintering profile and ultimately to a high density part and good mechanical properties. Surface area of particles, polymer viscosity and surface tension are characteristics which will be considered when modelling the flow and sintering process.

Performance improvement of electrical machines in terms of power-density and efficiency is central to the success of hybrid- and electric- vehicles and more- or all- electric aircraft, as indicated by the UK Advanced Propulsion Centre and the Aerospace Technology Institute. Efficiency and packaging volume of conventional electrical machines are limited by the method used to manufacture electrical windings, i.e. using pre-insulated conductors of uniform cross-section wound around the teeth of the stator. Here, we propose the use of metal additive manufacturing (3d printing), in which feedstock or powdered material is selectively bonded in a succession of 2D layers to incrementally form a compact 3D winding. The geometric freedom offered by additive manufacturing allows the simultaneous minimisation of end-winding volume and individual shaping of conductor profiles to optimise efficiency all while acting as a substrate for high performance inorganic electrical insulation materials. The technology could address the increasing drive to low batch size, flexibility and customisation in design for high integrity and high value electrical machines for the aerospace, energy and high value automotive sectors while enabling CO2 reductions demanded by legislation and market sentiment. Specifically, I will lead this multidisciplinary project exploring the potential benefits of Additive Manufacturing of High Performance Shaped Profile Electrical Machine windings leveraging expertise from industrial and academic partners Renishaw, 3TAM, Motor Design Ltd and Teesside University. The partners represent leading electrical machine design (Motor Design Ltd, University of Bristol), electrical insulation materials (Teesside University), UK additive manufacturing supply chain (Renishaw) and end-use additive manufacturing part production (3TAM). This range of partners cover the necessary skills and capability to go from theoretical winding design to manufactured, insulated prototype windings. As such, the project will result in a significant growth in the UK's knowledge and skills base in this area and develop a technology demonstrator to illustrate the quantitative benefit of such windings to industry and academia. This will allow new cross-sector relationships and collaborations to be cultivated with a view to perpetuate the research beyond the project period, ultimately leading to industrial adoption and further poising the UK as a centre for excellence in high value electrical machine technologies.

Step changes in electrical machine (e-machine) performance are central to the success of future More-Electric and All-Electric transport initiatives and play a vital role in meeting the UK's Net Zero Emission target by 2050. E-machine technology roadmaps from the Advanced Propulsion Centre (APC) and Aerospace Technology Institute (ATI) seek continuous power-density of between 9 and 25 kW/kg by 2035, in stark contrast to the 2-5 kW/kg available today. E-machine power-density is ultimately limited by the ability to dissipate internally generated losses, which manifest as heat, and the temperature rating of the electrical insulation system. The electrical conductors, referred to as windings, are often the dominant loss source and are conventionally formed from electrically insulated copper or aluminium conductors. Such conductors are manufactured using a drawing and insulation technique, which aside from improvements in materials, has seen little change in the past century. Exploring alternative manufacturing methods could allow reduction in losses, enhanced heat extraction and facilitate increased temperature ratings, ushering the necessary step changes in power-density and e-machine performance. Metal Additive Manufacturing (AM) is a process in which material is selectively bonded layer by layer to ultimately form a 3D part, enabling complex parts to be produced which may not be feasible using conventional methods. The design freedom offered by AM provides much sought-after opportunities to simultaneously reduce winding losses and packaging volume, improve thermal management and enable the use of high-temperature electrical insulation coatings. The design of such windings requires the development of new multi-physics design tools accounting for electromagnetic, thermo- and fluid- dynamics, mechanical and Design for AM (DfAM) aspects. It is important to have an understanding of the AM process, including the resulting material properties of parts and limitations on feature sizes and geometry in order to fully exploit the design freedoms whilst ensuring manufacturing feasibility. Establishing how to use build-supports and post-processes to improve component surface quality and facilitate application of electrical insulation coatings is another important aspect. To this end, I conducted initial studies in collaboration with academic and industrial partners focusing on shaped profile windings which have demonstrated the potential benefits of metal AM in e-machines and the drastic expansion of design possibilities to be explored. I intend to expand on this initial work through this fellowship which will provide me with flexible funding over a 4 + 3 year term to support The Electrical Machine Works, an ambitious and comprehensive research programme reminiscent of a Skunk Works project which draws together UK industry and academic expertise in AM, material science and multi-physics e-machine design to establish an internationally leading platform in this important emerging field. It is envisaged that the fellowship and associated platform, The Electrical Machine Works, will facilitate interdisciplinary collaboration with both industry and academia, catalysing high quality academic outputs disseminated through appropriate conference and journal publications, and the generation of Intellectual Property (IP), helping to keep the UK competitive in Power Electronics Machines and Drives (PEMD) and at the forefront of this area. If successful, in time The Electrical Machine Works will become a centre of excellence for AM in e-machines, contributing to a future skills and people pipeline and aiding in the raising of Technology Readiness Levels (TRL) in line with national priorities as expressed by the UK's Industrial Strategy, Advanced Propulsion Centre (APC), Aerospace Technology Institute (ATI) and Industrial Strategy Challenge Fund (ISCF) Driving the Electric Revolution (DER) and Future Flight (FF) initiatives.

Additive manufacturing has been hailed as representing the latest industrial revolution and has captured the imagination of expert users and the general public alike. New manufacturing capabilities have permitted us to explore new design freedoms and produce optimised products which are customised to the needs of the user. These trends are set to increase as the technology grows in capability and gathers credibility. There are an array of machine tools available on the market at the moment that can realise parts direct from digital. These make use of various energy sources (e.g Lasers, electron beams, IR lamps, heated nozzles etc) and material feedstocks (e.g metal/polymer powders, photocurable resins, plastic wires) to realise the design intent. Unlike more established machine tools there is a marked lack of process monitoring and feedback control of key process variables in these systems. This presents a significant problem since there is no method for ensuring that all is well within the build process. Therefore, in many cases it is only possible to identify defects after the process is complete assuming they are visible at the surface. Of significant concern, when integrity of parts is critical, are defects within the body of components. These can only be observed through cross sectioning or processes such as X-Ray Computed Tomography (CT). Naturally this comes at some considerable cost and only provides information once a part has been produced. Therefore, there is a real need for new methods to provide 'in process' information about the quality of the pre-fused material layer and the quality post melting. Clearly some penetration into the part is required to create a full picture which can be reconstituted in a layerwise manner to create an integrity map of parts upon completion. This can be used to identify buried regions which exhibit de-lamination, pores, cracking and density variations. Furthermore analysis of the deposition material pre melting should be able to identify voids and give some information about surface roughness and ideally material properties. Optical Coherence Tomography (OCT) is an imaging technique which, if tuned to the specific requirements of plastic imaging and applied in-situ within the AM tool, could be used to meet this challenge. This project will enable high-value additive manufacturing to come of age through implementation of sophisticated, in-situ, real-time process control based on novel non-contact optical techniques. OCT is a non-invasive imaging technique, which has the potential to revolutionise additive manufacturing technologies. It will bring additive manufacturing in line with established production processes with respect to product integrity, whilst also offering significant cost and resource efficiencies to support the widespread deployment of additive manufacturing tools throughout the manufacturing sector and to develop new and untapped applications. Appropriate high-speed OCT configurations aimed specifically at distinguishing between polymers of use in additive manufacturing are not currently available. Such a system will be built, integrating novel mid-IR components within an external cavity laser configuration, allowing vibration independent imaging of a range of single and multi-polymer parts. A successful outcome of this project will be the realization of an OCT system capable of rapid analysis of the sub-surface microstructure (e.g. voids and composition) of additively manufactured parts composed of multiple plastics, and a scheme for its incorporation into the additive process whereby in-situ monitoring of process integrity is enabled. Beyond this data sets will be gathered and post processed to evaluate and demonstrate the applicability of this new technology to additive manufacturing

The EPSRC Centre for Innovative Manufacturing in Additive Manufacturing will create a sustainable and multidisciplinary body of expertise that will act as a UK and international focus - the 'go to' place for additive manufacturing and its applications. The Centre will undertake a user-defined and user-driven programme of innovative research that underpins Additive Manufacturing as a sustainable and value-adding manufacturing process across multiple industry sectors.Additive Manufacturing (AM) is the direct production of end-use component parts made using additive layer manufacturing technologies. It enables the manufacture of geometrically complex, low to medium volume production components in a range of materials, with little, if any, fixed tooling or manual intervention beyond the initial product design. AM enables a number of value chain configurations, such as personalised component part manufacture but also economic low volume production within high cost base economies. This innovative approach to manufacturing is now being embraced globally across industry sectors from high value aerospace / automotive manufacture to the creative and digital industries. To date AM research has almost exclusively focused upon the production of single material, homogeneous structures (in polymers, metals and ceramics). The EPSRC Centre for Innovative Manufacturing in Additive Manufacturing will move away from single material, 'passive' AM processes and applications that exhibit conventional levels of functionality, toward the challenges of investigating next generation, multi-material active additive manufacturing processes, materials and design systems. This transformative approach is required for the production of the new generation of high-value, multi-functional products demanded by industry. The Centre will initially explore two themes as the centrepieces of a wider research portfolio, supported by a range of platform activities. The first theme takes on the challenge of how to design, integrate and effectively implement multi-material, multi-functional manufacturing systems capable of matching the requirements of industrial end-users for 'ready-assembled' multifunctional devices and structures. Working at the macro level, this will involve the convergence of several approaches to increase embedded value to the product during the manufacturing stage by the direct printing / deposition of electronic / optical tracks potentially on a voxel by voxel basis; the processing and bonding of dissimilar materials that ordinarily require processing at varying temperatures and conditions will be particularly challenging. The second theme will explore the potential for 'scaling down' AM for small, complex components, extending single material AM to the printing of optical / electronic pathways within micro-level products and with a vision to directly print electronics integrally. The platform activities will provide the opportunity to undertake both fundamental and industry driven pilot studies that both feed into and derive from the theme-based research, and grow the capacity and capability of the Centre, creating a truly national UK Centre and Network that maintains the UK at the front of international research and industrial exploitation in Additive Manufacturing.