There is a need for impact resistance light weight materials for a number of applications including, 1) for the aerospace industry, particularly satellites where protection from high speed space debris is required 2) ballistic personal armour. In this case, high quality light weight armour is essential to protect soldiers and to allow them function efficiently. In both cases high velocity impacts occur and weight is crucial. Boron carbide has the potential to be an excellent material as it is very hard and very light; however it unexpectedly fragments under shock or high pressure loading. We have shown in preliminary work that by carefully adjusting the chemistry of the material with small additions of Silicon the mechanism of fragmentation under high pressure loading is suppressed, although it is unclear if this translates to improved impact performance. Therefore in this work we aim to study in detail the mechanism by which boron carbide deforms and how this is altered by small additions of Silicon. This will involve deforming the materials within a high resolution electron microscope to understand which parts of the materials fail first and how. In parallel to these experiments, high velocity gas gun experiments on larger samples will help us understand how the deformation moves through the material, this is particularly important in impact resistant materials. Among other things this will require considerable improvements in our ceramic processing knowledge to produce the large amounts of the silicon stabilized boron carbide particularly for the gas gun experiments. However, if successful this knowledge will directly relevant to our industrial partners who will be able to quickly exploit it. The cutting edge analysis that will be required for this project will rely of devolvement of analytical techniques that can be applied in the future to a range of other materials. This includes high speed spectroscopic diagnostic tools which do not exist in the country at this time.

Some of the most pressing global issues today are related to energy consumption, dissipation and waste. There is a great promise to address these issues by developing high-performance, cost-effective and eco-friendly materials for thermoelectric applications. Here we plan to use state-of-the-art theoretical ab initio modelling approaches and state-of-the-art materials synthesis and processing techniques to develop high-efficiency copper-antimony-sulphide based thermoelectric compounds. These ternary compounds have attracted great interest in recent years due to appealing structural, electronic and thermal transport properties. Indeed, Cu-Sb-S compounds display a rich structural variety (ranging from rock-salt to layered structures), a large range of band gaps and are characterised by extremely low thermal conductivities.These features combined with the non-toxicity and abundance of the constituent elements make the Cu-Sb-S system an ideal playground to optimise materials for sustainable thermoelectric devices. Despite the intense research activity on these systems, many fundamental questions remain open, including the origin of the anomalously low thermal conductivity, the role of electronic correlation related to the presence of Cu d electrons, and the effect of defects, dopants and stoichiometry on transport properties as well as on the structural stability and thermo-mechanics of these compounds. Realising the full potential of these systems and producing optimised materials for industrial evaluation requires a combined theoretical and experimental effort. For this we bring together teams from KCL and QMUL with complementary expertise, respectively, in modelling transport properties in complex compounds via advanced first-principles techniques, and in synthesis, processing and characterization of thermoelectric materials. This effort will be crucial to enhance the performance and the stability of these compounds: the experimental work will provide a test for the theoretical approach and the theoretical predictions will guide the synthesis of optimised compounds. Together with our industrial partners (European Thermodynamics, Johnson & Matthey, Kennametal) we will also explore the production process and characterization of Cu-Sb-S-based thermoelectric modules.

The world around us is full of modern technology designed to make our lives safer, more comfortable and more efficient. Such technology is made possible by materials and devices that are able to interact with their surrounding environment either by sensing or acting upon it. Examples of such devices include motion detectors, fuel injectors, engine sensors and medical diagnostic tools. These interactive devices contain functional materials that can pose health hazards, are obtained from parts of the world where supply cannot be guaranteed or are relatively scarce. If access to these functional materials is restricted, many of these advances will no longer be available resulting in a reduction in living standards and decreased UK economic growth. There already exist a number of replacement materials that can provide the same functions without the same levels of concerns around safety, security of supply and sustainability. However, these replacement materials need to be manufactured using different processes compared to existing materials. This project explores new manufacturing technologies that could be used to create interactive devices that contains less harmful and sustainable materials with a secure supply. This project will focus on two types of material - thermoelectric and piezoelectric - where the replacement materials share a set of common challenges: they need to be processed at elevated temperatures; they contain elements that evaporate at high temperatures (making high temperature processing and processing of small elements difficult); they are mechanically fragile making it difficult to shape the materials by cutting, grinding or polishing; they are chemically stable making it difficult to shape them by etching; and many are air and moisture sensitive. The proposed research will address these challenges through three parallel research streams that proactively engage with industry. The first stream is composed of six manufacturing capability projects designed to develop the core manufacturing capabilities and know-how to support the programme. The second is a series of short term feasibility studies, conducted in collaboration with industry, to explore novel manufacturing concepts and evaluate their potential opportunities. Finally, the third stream will deliver focussed industrially orientated projects designed to develop specific manufacturing techniques for in an industrial manufacturing environment. The six manufacturing capability projects will address: 1) The production of functional material powders, using wet and dry controlled atmosphere techniques, needed as feedstock in the manufacture of bulk and printed functional materials. 2) How to produce functional materials while maintaining the required chemistry and microstructure to ensure high performance. Spark Plasma Sintering will be used to directly heat the materials and accelerate fusion of the individual powder particles using an electric current. 3) Printing of functional material inks to build up active devices without the need to assemble individual components. Combing industrially relevant printing processes, such as screen printing, with controlled rapid temperature treatments will create novel print manufacturing techniques capable of handling the substitute materials. 4) How to join and coat these new functional materials so that they can be assembled into a device or protected from harsh environments when in use. 5) The fitness of substituted material to be compatible with existing shaping and treatment stages found later in the manufacturing chain. 6) The need to ensure that the substitute materials do not pose an equal or greater risk within the manufacturing and product life cycle environment. Here lessons learned from comparable material systems will be used to help predict potential risks and exposures.

The conditions in which materials are required to operate are becoming ever more challenging. Operating temperatures and pressures are increasing in all areas of manufacture, energy generation, transport and environmental clean-up. Often the high temperatures are combined with severe chemical environments and exposure to high energy and, in the nuclear industry, to ionising radiation. The production and processing of next-generation materials capable of operating in these conditions will be non-trivial, especially at the scale required in many of these applications. In some cases, totally new compositions, processing and joining strategies will have to be developed. The need for long-term reliability in many components means that defects introduced during processing will need to be kept to an absolute minimum or defect-tolerant systems developed, e.g. via fibre reinforcement. Modelling techniques that link different length and time scales to define the materials chemistry, microstructure and processing strategy are key to speeding up the development of these next-generation materials. Further, they will not function in isolation but as part of a system. It is the behaviour of the latter that is crucial, so that interactions between different materials, the joining processes, the behaviour of the different parts under extreme conditions and how they can be made to work together, must be understood. Our vision is to develop the required understanding of how the processing, microstructures and properties of materials systems operating in extreme environments interact to the point where materials with the required performance can be designed and then manufactured. Aligned with the Materials Genome Initiative in the USA, we will integrate hierarchical and predictive modelling capability in fields where experiments are extremely difficult and expensive. The team have significant experience of working in this area. Composites based on 'exotic' materials such as zirconium diborides and silicon carbide have been developed for use as leading edges for hypersonic vehicles over a 3 year, DSTL funded collaboration between the 3 universities associated with this proposal. World-leading achievements include densifying them in <10 mins using a relatively new technique known as spark plasma sintering (SPS); measuring their thermal and mechanical properties at up to 2000oC; assessing their oxidation performance at extremely high heat fluxes and producing fibre-reinforced systems that can withstand exceptionally high heating rates, e.g. 1000oC s-1, and temperatures of nearly 3000oC for several minutes. The research planned for this Programme Grant is designed to both spin off this knowledge into materials processing for nuclear fusion and fission, aerospace and other applications where radiation, oxidation and erosion resistance at very high temperatures are essential and to gain a deep understanding of the processing-microstructure-property relations of these materials and how they interact with each other by undertaking one of the most thorough assessments ever, allowing new and revolutionary compositions, microstructures and composite systems to be designed, manufactured and tested. A wide range of potential crystal chemistries will be considered to enable identification of operational mechanisms across a range of materials systems and to achieve paradigm changing developments. The Programme Grant would enable us to put in place the expertise required to produce a chain of knowledge from prediction and synthesis through to processing, characterisation and application that will enable the UK to be world leading in materials for harsh environments.

The conditions in which materials are required to operate are becoming ever more challenging. Operating temperatures and pressures are increasing in all areas of manufacture, energy generation, transport and environmental clean-up. Often the high temperatures are combined with severe chemical environments and exposure to high energy and, in the nuclear industry, to ionising radiation. The production and processing of next-generation materials capable of operating in these conditions will be non-trivial, especially at the scale required in many of these applications. In some cases, totally new compositions, processing and joining strategies will have to be developed. The need for long-term reliability in many components means that defects introduced during processing will need to be kept to an absolute minimum or defect-tolerant systems developed, e.g. via fibre reinforcement. Modelling techniques that link different length and time scales to define the materials chemistry, microstructure and processing strategy are key to speeding up the development of these next-generation materials. Further, they will not function in isolation but as part of a system. It is the behaviour of the latter that is crucial, so that interactions between different materials, the joining processes, the behaviour of the different parts under extreme conditions and how they can be made to work together, must be understood. Our vision is to develop the required understanding of how the processing, microstructures and properties of materials systems operating in extreme environments interact to the point where materials with the required performance can be designed and then manufactured. Aligned with the Materials Genome Initiative in the USA, we will integrate hierarchical and predictive modelling capability in fields where experiments are extremely difficult and expensive. The team have significant experience of working in this area. Composites based on 'exotic' materials such as zirconium diborides and silicon carbide have been developed for use as leading edges for hypersonic vehicles over a 3 year, DSTL funded collaboration between the 3 universities associated with this proposal. World-leading achievements include densifying them in <10 mins using a relatively new technique known as spark plasma sintering (SPS); measuring their thermal and mechanical properties at up to 2000oC; assessing their oxidation performance at extremely high heat fluxes and producing fibre-reinforced systems that can withstand exceptionally high heating rates, e.g. 1000oC s-1, and temperatures of nearly 3000oC for several minutes. The research planned for this Programme Grant is designed to both spin off this knowledge into materials processing for nuclear fusion and fission, aerospace and other applications where radiation, oxidation and erosion resistance at very high temperatures are essential and to gain a deep understanding of the processing-microstructure-property relations of these materials and how they interact with each other by undertaking one of the most thorough assessments ever, allowing new and revolutionary compositions, microstructures and composite systems to be designed, manufactured and tested. A wide range of potential crystal chemistries will be considered to enable identification of operational mechanisms across a range of materials systems and to achieve paradigm changing developments. The Programme Grant would enable us to put in place the expertise required to produce a chain of knowledge from prediction and synthesis through to processing, characterisation and application that will enable the UK to be world leading in materials for harsh environments.