The UK has recently become the first major economy in the world committed to bring all greenhouse gas emission to net zero by 2050. The emphasis of the metal industry, a vital part of the UK's foundation industries, but a challenging area to deep decarbonise, is to develop new ways to produce and recycle metallic materials in an energy-efficient, low-cost and sustainable manner. Solidification is an important route for manufacturing and recycling of metals and alloys. Use of magnetic fields to control solidification has been researched for several decades with a variety of applications ranging from metal purification to advanced liquid metal processing. Successful examples include removing ceramic particles from aluminium melts and improving the internal quality of cast steels. There is huge potential for magnetic fields to be used in new applications such as metal recycling and advanced processing. Magnetic fields have a strong interaction with molten metals and alloys. The interaction is governed by the induced Lorentz force, which modulate the flow of the liquid molten alloys. My recent article [1] demonstrated that the interaction between magnetic fields and molten alloys can be controlled , paving the way towards novel methods for optimizing how magnetic fields can be used in industrial-scale manufacturing and recycling processes. I believe this technology will produce substantial improvements over the current state-of-the-art in process efficiency and materials performance. My recent patent (WO2020/012199A1) using this concept has shown that contaminated iron element in aluminium alloys can be driven out by magnetic fields when aluminium alloys are at the molten state, and subsequently the impurity can be removed effectively, a challenge that metallurgists have struggled to overcome after 40 years of research. The overarching aim of the Fellowship is to develop innovative magnet assemblies for materials manufacturing and recycling. This work will be underpinned by fundamental studies to uncover key underlying mechanisms. Based on my previous discovery and feasibility studies, in this Fellowship, I will develop patentable techniques utilizing magnetic fields for (1) the purification of recycled Al alloys, (2) the property improvement of high temperature alloys and (3) the microstructure control of metal additive manufacturing (3D printing). The Fellowship will accelerate the process of bringing the innovation from the lab to the market, as it provides unique opportunities to work with key industry partners. I will also address the underlying mechanisms for MHD control using a multidisciplinary approach, building upon my Turing Fellowship, coupling synchrotron based 4D (3D plus time) observation, data-driven analytics, and multi-physics modelling. This will not only lay strong foundations for process optimization, but also accelerate the development of entirely new solutions for incorporating MHD in manufacturing and recycling. The success of the Fellowship will increase the competitiveness of the UK's metal industries including aluminium recycling, casting, and additive manufacturing. [1] Cai et a. Acta materialia, 2020(196): 200-209 https://doi.org/10.1016/j.actamat.2020.06.041

Summary Unlike other materials for engineering applications, metals, such as aluminium and magnesium, can be recycled repeatedly without loss of their inherent properties. Recycling metals is not only economically viable, but also extremely beneficial for conservation of limited natural resources, reduction of energy consumption and waste generation, all contributing positively to a sustainable economy. One of the main barriers to the increased use of recycled light alloy scrap (both process scrap (new) and post consumer scrap (old)) is the existence of excessive levels of inclusions and impurity elements, which usually leads to downgrading into materials with poorer mechanical properties and reduced corrosion resistance. The prime objective of the proposed project is to break down this barrier and prevent market failure through the application of the step-change rheoforming technologies to allow the re-use of aluminium and magnesium alloy scrap in high-level automotive and other value added applications. The technical approach is to convert melts of recycled light alloy scrap into a semi-solid slurry using a twin screw slurry maker (TSSM) combined with a slurry accumulator and to feed this into a rheodiecaster for near net shape components, or a rheoextruder for continuous extruded profiles. Owing to the intensive forced convection in the TSSM, both inclusions and impurity elements (usually as intermetallic compounds in the solidified microstructure) will be divided into extremely fine particles and dispersed uniformly throughout the entire casting, eliminating/reducing the detrimental effects to ductility and corrosion resistance. This will result in extensive materials re-use, producing castings and extruded sections of aluminium and magnesium alloys made from selected combinations of post consumer scrap (PCS) supplied by Norton Aluminium and magnesium diecasting scrap supplied by Meridian. The mechanical performance and corrosion properties of the rheoformed products will be assessed against current production aluminium and magnesium castings and wrought products made from conventional primary metal based melts. For magnesium the emphasis of the project will be on production of rheodiecastings with a much smaller activity on wrought products, whilst for aluminium the emphasis will be both on high performance castings and on wrought products, particularly rheoextrusions. The work at BCAST will focus on the following aspects: (1) As the technology provider, BCAST team will focus on developing the rheoforming technologies, particularly the rheo-diecasting and the rheoextrusion processes, for upcycling light alloy scrap into high quality components for automotive and other general engineering applications. This will include design, commissioning and optimisation of the rheoextruder, integration of the rheoextruder with the slurry supply system. (2) The BCAST team will characterise the chemical compositions, microstructures, mechanical properties and corrosion resistance of rheoformed products produced from different scrap sources. The results will feed into the process optimisation programme as guidelines, and will also be used to understand the relationships between chemical composition, processing conditions and engineering performance. (3) The BCAST team will assist the industrial scale trials for rheoforming Al scrap at Norton Aluminium and for rheo-diecasting of magnesium scrap at Meridian. The project will develop a unique UK partnership of material producers, recyclers, technology providers and product manufacturers to develop a novel processing route for increasing the re-use and recycled content of light alloy materials by upcycling into higher-value products. Such a collaborative development will enable rapid UK commercial exploitation and will reduce dependency on imported products.

Natural resources are the foundation of our life on Earth, without which neither our economy nor society can function. However, due to continued resource overconsumption and the rapidly increasing world population, the global demand for natural resources and the related intense pressure on our environment have reached an unprecedented and unsustainable level. A shocking fact is that our cumulative consumption of natural resources over the last 60 years is greater than that over the whole of previous human history. With an anticipated world population of 9.3bn in 2050, the predicted global natural resource consumption will be almost tripled. This level of overconsumption is obviously not sustainable, and there is a compelling need for us to use our advanced science and technology to work with, rather than to exploit, nature. Metallic materials are the backbone of manufacturing and the fuel for economic growth. However, metal extraction and refining is extremely energy intensive and causes a huge negative impact on our environment. The world currently produces 50MT of Al and 2bnT of steel each year, accounting for 7-8% of the world's total energy consumption and 8% of the total global CO2 emission. Clearly, we cannot continue this increasing and dissipative use of our limited natural resources. However, the good news is that metals are in principle infinitely recyclable and that their recycling requires only a small fraction of the energy required for primary metal production. Between 1908 and 2007 we produced 833MT of aluminium, 506MT of copper and 33bnT of steels. It is estimated that more than 50% of this metal still exists as accessible stock in our society. Such metal stock will become our energy "bank" and a rich resource for meeting our future needs. The UK metal casting industry adds £2.6bn/yr to the UK economy, employs 30,000 people, produces 1.14bnT of metal castings per year and underpins the competitive position of every sector of UK manufacturing. However, the industry faces severe challenges, including "hollowing-out" over the past 30 years, increasing energy and materials costs, tightening environmental regulations and a short supply of skilled people. We are now establishing the Future Liquid Metal Engineering Hub to address these challenges. The core Hub activities will be based at Brunel strongly supported by the complementary expertise of our academic spokes at Oxford, Leeds, Manchester and Imperial College and with over £40M investment from our industrial partners. The Hub's long-term vision is full metal circulation, in which the global demand for metallic materials is met by a full circulation of secondary metals (with only limited addition of primary metals each year) through reduced usage, reuse, remanufacture, closed-loop recycling and effective recovery and refining of secondary metals. This represents a paradigm shift for metallurgical science, manufacturing technology and the industrial landscape. The Hub aims to lay down a solid foundation for full metal circulation, demonstrated initially with light metals and then extended to other metals in the longer term. We have identified closed-loop recycling of metallic materials as the greatest challenge and opportunity facing global manufacturing industry, and from this we have co-created with our industrial partners the Hub's research programme. We will conduct fundamental research to deliver a nucleation centred solidification science to underpin closed-loop recycling; we will carry out applied research to develop recycling-friendly high performance metallic materials and sustainable metal processing technologies to enable closed-loop recycling; we will operate a comprehensive outreach programme to engage potential stakeholders to ensure the widest possible impact of our research; we will embed a centre for doctoral training in liquid metal engineering to train future leaders to deliver long-lasting benefits of closed-loop recycling.

The UK metal casting industry is a key player in the global market. It adds 2.6bn/year to the UK economy, employs directly around 30,000 people and produces 1.14 billion tons of metal castings, of which 37% is for direct export (Source: CMF, UK). It underpins the competitive position of every sector of UK manufacturing across automotive, aerospace, defence, energy and general engineering. However, its 500 companies are mainly SMEs, who are often not in a position to undertake the highest quality R&D necessary for them to remain competitive in global markets. The current EPSRC IMRC portfolio does not cover this important research area nor does it address this clear, compelling business need. We propose to establish IMRC-LiME, a 3-way centre of excellence for solidification research, to fill this distinctive and clear gap in the IMRC portfolio. IMRC-LiME will build on the strong metal casting centres already established at Brunel, Oxford and Birmingham Universities and their internationally leading capabilities and expertise to undertake both fundamental and applied solidification research in close collaborations with key industrial partners across the supply chain. It will support and provide opportunities for the UK metal casting industry and its customers to move up the value chain and to improve their business competitiveness. The main research theme of IMRC-LiME is liquid metal engineering, which is defined as the treatment of liquid metals by either chemical or physical means for the purpose of enhancing heterogeneous nucleation through manipulation of the chemical and physical nature of both endogenous (naturally occurring) and exogenous (externally added) nucleating particles prior to solidification processing. A prime aim of liquid metal engineering is to produce solidified metallic materials with fine and uniform microstructure, uniform composition, minimised casting defects and hence enhanced engineering performance. Our fundamental (platform) research theme will be centred on understanding the nucleation process and developing generic techniques for nucleation control; our user-led research theme will be focused on improving casting quality through liquid metal engineering prior to various casting processes. The initial focus will be mainly on light metals with expansion in the long term to a wide range of structural metals and alloys, to eventually include aluminium, magnesium, titanium, nickel, steel and copper. In the long-term IMRC-LiME will deliver: 1) A nucleation-centred solidification science, that represents a fundamental move away from the traditional growth-focused science of solidification. 2) A portfolio of innovative solidification processing technologies, that are capable of providing high performance metallic materials with little need for solid state deformation processing, representing a paradigm shift from the current solid state deformation based materials processing to a solidification centred materials engineering. 3) An optimised metallurgical industry, in which the demand for metallic materials can be met by an efficient circulation of existing metallic materials through innovative technologies for reuse, remanufacture, direct recycling and chemical conversion with limited additions of primary metal to sustain the circulation loop. This will lead to a substantial conservation of natural resources, a reduction of energy consumption and CO2 emissions while meeting the demand for metallic materials for economic growth and wealth creation.

To avoid global warming and our unsustainable dependence on fossil fuels, the UK's CO2 emissions are recommended to be reduced by 80% from current levels by 2050. Aerospace and automotive manufacturing are critical to the UK economy, with a turnover of 30 billion and employing some 600,000 worker. Applications for light alloys within the transport sector are projected to double in the next decade. However, the properties and cost of current light alloy materials, and the associated manufacturing processes, are already inhibiting progress. Polymer composites are too expensive for body structures in large volume vehicle production and difficult to recycle. First generation, with a high level of recycling, full light alloy aluminium and magnesium vehicles in production are cheaper and give similar weight savings (~ 40%) and life cycle CO2 footprint to low cost composites. Computer-based design tools are also playing an increasing role in industry and allow, as never before, the optimisation of complex component architectures for increased mass efficiency. High performance alloys are still dominant in aeroengine applications and will provide ~ 30% of the structural components of future aircraft designs, where they will have to be increasingly produced in more intricate component shapes and interfaced with composite materials.To achieve further weight reductions, a second generation of higher performance light alloy design solutions are thus required that perform reliably in service, are recyclable, and have more complex product forms - produced with lower cost, energy efficient, manufacturing processes. With design optimisation, and by combining the best attributes of advanced high strength Al and Mg alloys with composites, laminates, and cheaper steel products, it will be possible to produce step change in performance with cost-effective, highly mass efficient, multi-material structures.This roadmap presents many challenges to the materials community, with research urgently required address the science necessary to solve the following critical issues: How do we make more complex shapes in higher performance lower formability materials, while achieving the required internal microstructure, texture, surface finish and, hence, service and cosmetic properties, and with lower energy requirements? How do we join different materials, such as aluminium and magnesium, with composites, laminates, and steel to produce hybrid materials and more mass efficient cost-effective designs? How do we protect such multi-material structures, and their interfaces against corrosion and environmental degradation?Examples of the many scientific challenges that require immediate attention include, how can we: (i) capture the influence of a materials deformation mechanisms, microstructure and texture on formability, thus allowing computer models to be used to rapidly optimise forming for difficult alloys in terms of component shape and energy requirements; (ii) predict and control detrimental interfacial reactions in dissimilar joints; (iii) take advantage of innovative ideas, like using lasers to 'draw on' more formable microstructures in panels, where it is needed; (v) use smart self healing coating technologies to protect new alloys and dissimilar joints in service, (vi) mitigate against the impact of contamination from recycling on growth of oxide barrier coating, etc.A high priority for the Programme is to help fill the skills gap in metallurgical and corrosion science, highlighted in the EPSRC Review of Materials Research (IMR2008), by training the globally competitive, multidisciplinary, and innovative materials engineers needed by UK manufacturing. The impact of the project will be enhanced by a professionally managed, strategic, research Programme and through promoting a high international profile of the research output, as well as by performing an advocacy role for materials engineering to the general public.