Human society is highly dependent on the Earth's climate, as climate patterns largely determine whether we will have enough food and fresh water. The gradual increase in the global temperature, due primarily to the increased amount of an undesirable gas, CO2, in the atmosphere, can cause significant climate changes. Road transport activities account for about 24% of the total man-made CO2 released to the atmosphere, and passenger cars are responsible for about 60% of these emissions. It is therefore an important issue to reduce the CO2 emissions from passenger cars in order to prevent the Earth's climate from deteriorating. One of the most efficient and easiest ways to do this, is to reduce the weight of a car so that the car will burn less petrol or diesel. Magnesium is a very light metal, in fact, some magnesium materials can be made lighter than water. On the other hand, they are still strong enough for making most of the parts used in a car. Therefore, they are very attractive to car manufacturers.Just like a sand castle that is made of many grains of sand, magnesium materials are composed of many small grains as well. The grain size in a magnesium material plays a very important role in determining whether the material is ductile or not. In general, the smaller the grain size, the more ductile the magnesium material will be. It is thus highly beneficial for magnesium materials to have a very small grain size, so that we can readily manufacture them into different shapes, such as sheet, tubes, bars, rods, etc. These forms of magnesium products are all very useful for making car parts and parts used in toys, bicycles, computers, mobile phones, televisions, etc. Unfortunately, large, thick magnesium materials normally have a coarse grain size, as a result, they are not ductile enough. Therefore, one has to use a very slow manufacturing process to make magnesium sheet, tubes, bars, rods, etc. This makes them very expensive and not many customers including most car manufacturers, are willing to use them in a large quantity. It is therefore crucial to reduce their grain size. Similar to the process of water becoming ice, solid magnesium materials start off as liquid magnesium. The change from liquid to solid is called solidification, which determines the grain size of a magnesium material. By effectively controlling the solidification process one can obtain a very fine grain size. In the past 65 years, there have been many efforts towards controlling the solidification process of magnesium materials. Although there have been some positive developments, the resultant grain size is still not small enough. In this programme, we propose a unique approach, designated 'twin-screw melt shearing'; it can effectively control the solidification of a magnesium material. The key point of this approach is to ensure that as many small grains as possible survive in the liquid during solidification. This is done by rapidly lowering the bulk liquid temperature to below a critical value; in doing so, the process will give a very fine and uniform grain size. Preliminary experiments have given very encouraging and exciting results, suggesting that the concept is feasible. Therefore it is hoped that further study into this new solidification control process will develop a hugely beneficial processing system, which will be able to deliver a fine grain size in large, thick magnesium products. It is further anticipated that the new technology will also be applicable to the solidification of other materials, such as aluminium and titanium.The anticipated results from this study will be both environmentally and economically beneficial to the global community.

In 2008 the annual financial cost to the UK arising from corrosion damage to metals was $70.6 billion. In addition to the financial cost, the threat of corrosion limits the range of materials that can be safely or reliably deployed. The principal reason why magnesium alloys are not as ubiquitous as the denser aluminium is their susceptibility to aqueous corrosion even in reasonably dry air. Titanium alloys are more corrosion resistant, but in the aerospace sector suffer stress corrosion cracking following degreasing in chlorine-containing agents, or even after handling by salty fingers! When titanium is used for medical implants, corrosion is a principal cause of failure; for example, localised wear of an implant exposes a small area of metal establishing a large anodic current density and localised metal wastage. Both industry and academia agree there is an urgent need to arrive at an understanding of corrosion and passivation at the atomic scale. Modern experimental methods include electrochemical scanning tunnelling microscopy in which the tip makes an atomic resolution image of the surface as it is corroding under an applied overpotential. It is time for theory and simulation to catch up! First principles quantum mechanics has been used very successfully to make accurate and detailed calculations of both measurable and not measurable quantities central to the theory and practice of corrosion: for example, the potential of zero charge and the Galvani potential. But these are equilibrium quantities. We need to know the transmission coefficient, to solve the Butler-Volmer equation and to use atomistic simulation as it is intended: as a "microscope" to view the dynamical world at the scale of electrons and atoms. Then we can delve into the structure of the non equilibrium double layer. We here propose a novel scheme for the simulation of corrosion using molecular dynamics and kinetic Monte Carlo methods, in which we can follow the dissolution of metal ions and their transport through the double layer and into the electrolyte, and the formation and transport through a passive film, at both constant overpotential and constant current. Our most ambitious vision is to deal with localised attack: pitting and crevice corrosion. Our claim is that we can achieve this by marrying two recently demonstrated theories. These are the polarisable-ion tight binding theory (PITB), and the Hairy Probes formalism for electron open boundaries. The tight binding hamiltonian is an empirical surrogate for that of the first principles density functional theory, and the PITB is able to describe quantum electrons, ionic, covalent and metallic bonding, bond making and breaking, charge transfer and polarisable ions. The method was demonstrated recently for a wide spectrum of condensed matter, including metals, metal oxides and water. The Hairy Probes refer to a way to inject electrons into a "device region" by the maintenance of controlled electrochemical potentials at the left and right hand parts of a simulation box of atoms. The two investigators have developed these theories. Our approach will be further to develop the required computer codes and to extend the tight binding method to describe magnesium, in addition to titanium for which a tight binding hamiltonian already exists. We will demonstrate uniform corrosion and after validating against known electronic structure calculations, we will leap into the unknown. We will test current thinking about the asymmetry of the electro-capilliarity curves; make simulations of uniform corrosion of bare metal and through oxide layers and compute Evans diagrams. In parallel we will address two case studies in corrosion that have been proposed to us by our industrial project partners. These are to look at the negative difference effect in magnesium and to investigate failure of the passive layer in aerospace titanium alloys when exposed to chloride environments.

Research into solid adsorbents for CO2 is motivated by their potential advantages over liquid amine, membrane or cryogenic separation techniques in mid-high temperature CO2 separation, for example, in hydrogen production via steam reforming/gasification of waste biomass where production yields are increased through the use of a sorbent powder such as CaO that chemically binds the CO2 from the mixed product stream and shifts the reaction thermodynamics to increase hydrogen output. There are also applications in large scale CO2 capture involving integration with fossil fuel fired power stations, and other industries. This materials engineering based proposal addresses the major problem facing utilisation of powder sorbents such as CaO for high temperature applications, including hydrogen production by sorbent enhanced steam reforming (SESR) of waste biomass. A decay in CO2 capture performance due to changes in the structure of the powder bed (densification) during regeneration at high temperatures prevents full exploitation of this promising technology in SESR and large scale CO2 capture applications. Significant powder densification occurs after heat-treatments at > 800 C to release CO2 and regenerate the sorbent. This leads to loss of porosity and sorbent surface area, causing a serious decay in CO2 capture performance. Developments in recent years, for example, adding refractory spacer particles are only successful for non-optimal regeneration conditions (e.g. < 850 C in inert atmospheres). The powders to be developed in this 18 month feasibility study will exploit a novel means of counteracting densification and loss of surface area, aiming to achieve regeneration at 950 C (much higher than for existing sorbents) in atmospheric conditions without significant decay in CO2 sorption capacity. An important advantage of the new powders is that a near-pure CO2 stream will be generated during regeneration at 950 C, producing output streams suited to integration with CO2 storage and/or utilisation programmes; this contrasts to the mixed gas streams generated at lower temperatures using existing materials. The new approach to the durability problem is to disperse ultrafine particles of partially stabilised zirconia (PSZ) in the sorbent matrix. The PSZ particles undergo a phase transition on cooling after regeneration which results in an increase in particle (crystallite) volume. Resulting strains generated in the surrounding, partially sintered, sorbent matrix will cause microcracks and secondary strain fields to develop which will open up pore channels for ingress of gasses. Loss of CO2 capture capacity in the subsequent sorption step will thus be mitigated, even for technologically favoured high regeneration temperatures (950 C), leading to increased multi-cycle sorbent efficiency, and increased hydrogen yield in SESR. The anti-densification mechanism will also be evaluated for an alternative CO2 sorbent, Na2ZrO3.

Zirconia-based ceramics are used in many engineering applications but they fail when exposed to moisture at 100 300oC. Overcome this and major new markets open up in the medical and petrochemical industries amongst many others. Results obtained by Loughborough University indicate this can be achieved by producing nanostructured zirconia.The science is now largely understood so the task is to scale up the manufacture of these materials to prototype level and transfer the technology into industry. Three industrial partners, including a nanopowder producer, a ceramic manufacturer and a control valve manufacturer, will work with Loughborough to achieve this.

Solid oxide fuel cells have the potential to greatly reduce carbon emissions in electricity generation because of their high conversion efficiency and suitability for distributed generation. Overall, this project will target the critical fuel cell issues of system cost and lifetime, including cell and stack cost, power density and affordability. The research will focus on the design, development and validation of novel components, sub-systems and integrated systems for RRFCS's initial system, a 1MW SOFC stationary power generation unit. Imperial College will contribute by developing new low-cost materials and geometries that are fundamental to the realisation of competitive fuel cells and stacks. This will involve using theoretical modelling at the atomistic level to identify promising new materials with the appropriate electronic properties. These will be synthesised and characterised in detail and finally the most promising ones will be evaluated in the RRFCS fuel cell structure.