As you read this you are probably sitting down. When you sat down, were you concerned that the chair would fail? You likely did not even consider it as you may have sat in this same chair hundreds, if not thousands of times before. You used your empirical knowledge that this chair is safe for you to sit in. What if this was a new chair to you? If the chair was brand new, you would take comfort in the fact that the chair has been manufactured to a standard and been subject to some level of quality control. If the chair belongs to an organisation then you would expect that organisation to take responsibility if the chair failed and would have been replaced if reported by another user. Failure of the chair will, very rarely, be due to a poor design. The chair will be able to withstand any expected loads assuming that it has been manufactured correctly; however, the material that it is made from will be inherently variable and contain defects that are not always apparent at the point of a manufacturing inspection. The degree of that material variability may be slight and the defect sizing understood, but making sure that the design takes account of this variability through life (especially when the chair is mistreated) is often not considered. To some extent we are all materials engineers when we make a judgement that the chair appears to be 'sturdy' before we sit down, but we do this based on our empirical knowledge and not on the science that is available to us. Are you sure the next time you sit in the chair it won't fail? Your empirical knowledge only informs you of what happened last time not what 'will' happen in the future. The application of materials science knowledge will inform the future performance. Bridging the gap between the atomistic world of materials science that defines the best estimate of mechanical performance and the bounding estimates required in materials engineering that takes account of the variability and defects is key to improving trust in applying materials science to engineering structures. Assurance is about the trust that we place that the quality system has not failed. The chair may have been subject to a level of quality control before it left the factory, at this stage we need to have trust in the manufacturer. If the chair belongs to an individual or organisation, we trust that as responsible owners, that they would replace the chair if broken and that they have systems in place to check if the chair is broken before someone sits on it. This fellowship is about developing a similar level of trust for future high integrity or critical applications. We cannot use empirical knowledge, i.e. we don't have thousands of years of experience with building fusion reactors or producing high integrity power transmission systems for aerospace applications, so we must use science. Developing a similar level of trust in the predictive modelling capability in the application of materials science to these complex and high value systems, to the empirical knowledge we all have of our usual chair is key to unlocking the public trust in the safe performance of future critical systems.

As you read this you are probably sitting down. When you sat down, were you concerned that the chair would fail? You likely did not even consider it as you may have sat in this same chair hundreds, if not thousands of times before. You used your empirical knowledge that this chair is safe for you to sit in. What if this was a new chair to you? If the chair was brand new, you would take comfort in the fact that the chair has been manufactured to a standard and been subject to some level of quality control. If the chair belongs to an organisation then you would expect that organisation to take responsibility if the chair failed and would have been replaced if reported by another user. Failure of the chair will, very rarely, be due to a poor design. The chair will be able to withstand any expected loads assuming that it has been manufactured correctly; however, the material that it is made from will be inherently variable and contain defects that are not always apparent at the point of a manufacturing inspection. The degree of that material variability may be slight and the defect sizing understood, but making sure that the design takes account of this variability through life (especially when the chair is mistreated) is often not considered. To some extent we are all materials engineers when we make a judgement that the chair appears to be 'sturdy' before we sit down, but we do this based on our empirical knowledge and not on the science that is available to us. Are you sure the next time you sit in the chair it won't fail? Your empirical knowledge only informs you of what happened last time not what 'will' happen in the future. The application of materials science knowledge will inform the future performance. Bridging the gap between the atomistic world of materials science that defines the best estimate of mechanical performance and the bounding estimates required in materials engineering that takes account of the variability and defects is key to improving trust in applying materials science to engineering structures. Assurance is about the trust that we place that the quality system has not failed. The chair may have been subject to a level of quality control before it left the factory, at this stage we need to have trust in the manufacturer. If the chair belongs to an individual or organisation, we trust that as responsible owners, that they would replace the chair if broken and that they have systems in place to check if the chair is broken before someone sits on it. This fellowship is about developing a similar level of trust for future high integrity or critical applications. We cannot use empirical knowledge, i.e. we don't have thousands of years of experience with building fusion reactors or producing high integrity power transmission systems for aerospace applications, so we must use science. Developing a similar level of trust in the predictive modelling capability in the application of materials science to these complex and high value systems, to the empirical knowledge we all have of our usual chair is key to unlocking the public trust in the safe performance of future critical systems.

To achieve the UK zero carbon emission target by 2050, alternative energy generation with zero CO2 emission, such as wind, solar, and nuclear energy, is now the target of urgent development to completely replace the use of fossil fuels such as coal, oil, and natural gas. However, the widely used nuclear fission reactors have many issues, for example, the difficulty of nuclear waste treatment and storage and the risk of uncontrolled chain reactions. On the other hand, nuclear fusion energy has many potential advantages, for example, four times higher energy than fission, abundant hydrogen and its isotopes as the fuel, and the short lifespan of the radioactive waste products. However, the development of fusion reactors puts a high demand on materials, as these must withstand high energy levels, high transmutation rates, high temperatures, and high thermomechanical stresses. This brings major material design challenges and requires the design and development of superior materials, along with innovative, facile, manufacturing routes, especially for the first wall structures and breeder blanket of fusion reactors. The structure is not only irradiated by the plasma but also undergoes neutron bombardment from the plasma, as well as high loadings of helium and hydrogen, which causes serious damage to the structural materials. Currently, one of the potential materials designed for the first wall and blanket structures on the fusion reactors is the reduced activation ferritic/martensitic (RAFM) steels, due to the superior thermal conductivity, relatively low thermal expansion, and resistance to radiation-induced swelling and helium embrittlement, as well as the easy commercial process, compared to other materials. However, the properties of these RAFM steels restrict their maximum operating temperature to only 550C, which is much lower than the service temperature of 650C. Moreover, irradiation induces the hardening of these steels at lower service temperatures (250-350C) and embrittlement at high temperatures (450-550C), which also restricted their application. Thus, the 3rd generation oxide dispersion strengthened (ODS) RAFM steels have been developed through nanoparticle and ultra-fine grains, which successfully increase the operating temperature to 650C. However, the limitation of the ODS RAFM steels is the obvious difficulty in powder manufacturing at a sufficient scale to be used in the first wall and blanket structures in fusion reactors. ODS steels also have a problem with a high ductile to the brittle transition temperature. This severely limits their applicability. Thus, there is still an urgent need to develop new RAFM steels for the structure materials on fusion reactors with a service temperature of 650C and easy manufacturing to various scales and structures. In this project, according to ODS RAFM steels, the guiding principles of a fine structure and a high-temperature stable precipitate phase will be used to design new, processable, RAFM steels. For example, the intermetallic precipitates and carbonitrides, which have a lower coarsening rate than carbides at high temperatures, will be the target precipitates; these can be achieved through alloy design with corresponding heat treatment. Moreover, grain refinement can be achieved through the modification of the manufacturing process, for example, by using ausforming, which will produce an extremely high dislocation density. Subsequently, during heat treatment, these dislocations will form nanoscale subgrains through recovery and recrystallization. Thus, the ultimate goal of the research will be to produce new RAFM steels for supply to the spherical tokamak (STEP). This requires advances to allow materials selection between 2023 to 2025 and provision to produce net electricity from fusion in 2040. It will also support the UK to be the world leader in fusion materials design and develop this prominent position through cutting-edge research on groundbreaking material systems

Steel continues to be the most used material in the world by value and play an essential role in all aspects of society, from construction to transport, energy generation to food production. The long-term sustainability of UK steel making requires lower energy production and the development of high value steel products. The ability to measure the microstructure of steel in a non-contact, non-destructive fashion can lead to dramatic improvement in the understanding of the material and its behaviour during processing and in-service. Improved control during processing will increase efficiency in production of complex steel microstructures and allow new generation alloys to be made. Through our previous EPSRC and industry funded research we have created a new electromagnetic (EM) measurement system, EMspecTM, that can monitor the microstructure of strip steel during hot processing. This system is now providing information related to the condition (transformed phase fraction) of the microstructure over 100% of the strip length. The scene is now set to make the next major step forward with the information that new in-line microstructure measurement systems can offer - proposed real-time in-line microstructural engineering, or 'RIME' technology. Our ambition is to enable real-time microstructure engineering during processing via dynamic control of cooling strategies or heat treatment using EM sensor feedback, in particular to engineer microstructures that were previously either impossible to achieve in full scale production or could not be reliably achieved. This will require detailed knowledge of the full temperature - magnetic - microstructure parameter space and sensors that are capable of operating in elevated temperature environments (such as heat treatment facilities), which are not currently available outside the laboratory. In addition application to a wide range of product lines, from strip to plate or sections requires integration of through thickness cooling models and EM signal-depth interpretation all mapped for varying temperature and phase fraction. In this project we will develop new sensors that can operate at high temperature; both laboratory systems to determine full magnetic properties with temperature for model and commercial steels, essential information that is currently unavailable in the literature, and robust deployable sensors for trials in industrial conditions; and systems designed to interrogate for through thickness data. We will develop a demonstration facility, consisting of a furnace, run out table with cooling sprays and EMspecTM system, to allow dynamic feedback control of cooling schedules from EM sensor signals to engineer specific microstructures. Alongside the hardware and demonstration activities we will also develop modelling capabilities, both for sensor design and signal interpretation: our current models are used to relate sensor signals to microstructure (phase fraction and grain size at room temperature) with incorporation of temperature effects planned in this project. A number of case studies have been identified to trial the new technologies including advanced high strength strip steels (AHSS) for light-weighting of vehicles, high strength - high toughness pipeline steels for demanding environments, high strength, more uniform, constructional steels and tailoring microstructure in rod.

Hydrogen is the lightest of the elements and has some remarkable properties and uses. Its isotopes will provide the nuclear fusion fuel for humanity in the next half century. Even now, it is probably the cleanest available fuel for motor cars and its extraction from sea water using solar power and subsequent transport around the globe is mooted as a potential solutions to our energy crisis. Because of its atomic size, hydrogen is not easy to contain as it diffuses readily through the lattice of solid materials, frequently by quantum mechanical tunnelling. The problem has a darker side; hydrogen has been known for over a hundred years to cause catastrophic failure in high strength steels. All welders know to keep their manual metal arc electrodes dry to avoid the generation of hydrogen from the decomposition of water during welding. The alloys resulting from our experiments and modelling will impact directly on the fuel efficiency of the next generation of automobiles, the service lifetimes of wind turbines and pipelines and lead to the development of new valve gear, and hydrogen handling and transport systems. We expect this to lead to improved profitability of our project partners and the sustainability of UK industry. The project will develop new design procedures for ultra-high strength steels that resist embrittlement due to the presence of hydrogen for use in the above applications . This will be achieved through a series of advances in materials characterisation, testing and modelling. New experimental techniques will be developed to identify the structure of defects in engineering alloys and how they trap hydrogen. Understanding this trapping process is a key step in understanding how and why hydrogen embrittles steels. A range of modelling techniques from the atomistic through to the continuum will be developed and employed to provide detailed information about the embrittling mechanisms and how these depend on the steel microstructure. This will allow microstructures to be identified that are resistant to hydrogen embrittlement. This information will be employed to guide the development of new procedures for the design of alloys and heat treatments that result in steels that are resistant to attack by hydrogen. These techniques will be validated by processing a range of new alloys designed using our new methodology and examining their mechanical performance in the presence of hydrogen.