Background The potential for magnesium-based products is great owing to their lower weight than similar products. However, current processes for transforming magnesium and related alloys into components for industrial use have significant cost and environmental drawbacks. Current production techniques require high temperatures (up to 600° C) and are thus energy intensive. They also involve the use of highly polluting greenhouse gases to protect the liquid metal. The current approach requires a range of different steps that generally take place across different locations. As a consequence, semi-finished raw materials often need to be transported from one processing plant to another, resulting in negative environmental impacts across the whole life cycle. Objectives The Green Metallurgy project aimed to demonstrate that it is possible to manufacture magnesium-based larger scale, complex-shape structural elements that can be used in place of classic automotive parts. Use of such components would result in a substantial weight reduction by directly substituting heavier steel or cast iron components, which make up on average some 64% of the weight of a car, with lighter components. The project would therefore demonstrate on an industrial scale an innovative single-step manufacturing process with a substantially reduced carbon dioxide footprint compared with current methods. The end result would be automotive parts made from high-performing, lightweight materials. The project would also show how energy use can be reduced during the production process, leading to fewer greenhouse gas emissions over component life cycles. Results The Green Metallurgy project tested and demonstrated, on a preliminary laboratory scale, the feasibility and benefits of producing and using two innovative non-commercial materials: high-performance nano-structured magnesium alloy, BAS, and a fully recycled low-impact magnesium alloy, Eco-Mg. These materials – especially the high-performance BAS (which has strong mechanical properties and a different ductility from conventional commercial magnesium material) – could be suitable for use in light structural components for a range of industrial sectors. (It is foreseen that they would address the weight-saving targets of car makers thanks to their structural composition.) After the preparatory phase, the project team set up a prototype plant for demonstrating the possibility of obtaining on a pre-industrial scale the abovementioned products using a non-melting, low-impact process (lower energy consumption and fewer CO2 equivalent emissions overall). This process completely avoids the use of high-impact protective gases needed to prevent magnesium oxidation and burning that can occur in a melting state. The following environmental benefits were achieved: An increase of the mechanical resistance of magnesium alloys to compete with aluminium and steel as well as with the light-weight material Carbon Fiber Reinforced Polymer (CFRP): BAS were shown to have the expected mechanical resistance, elongation and grain-size, and were demonstrated to be a high-performance material. The mechanical properties of Eco-Mg were in line with the conventional material used in the automotive sector though both low carbon steel and aluminium alloys are heavier than Eco-Mg (magnesium is 70% lighter than steel and 30% lighter than aluminium). Moreover, the material has the same properties as Carbon Fiber Reinforced Polymers but is 56.4% lighter than steel pan. Reduction of CO2 emissions and energy content in the production stage: The project demonstrated that it is possible to clean up the fabrication process stage, thus allowing a net positive balance (calculated in 180kg scenario of magnesium on board) of at least 16% of the total CO2 emitted over the whole lifecycle. The pilot plant is energy efficient since it operates on a fully solid state, avoiding any melting stages. It thus reduces energy consumption by up to 80% compared to conventional process routes that have a melting phase. In addition, the project managed to produce complex geometry samples, directly using bars from the pilot plant, for both thin articulated shapes and monolithic complex shapes, thanks to the super-plastic properties of the materials. These were produced from powders under temperatures of 250° C over the entire process. However, the expected result of maintaining the temperature throughout the production process below 200° C (compared to 300° C in the traditional process) was not fully reached. Elimination of protective gases: The developed process completely eliminated SF6 and other high-impact protective gases needed to prevent magnesium oxidation and burning that can occur in a melting state. The plant thus completely avoids greenhouse gas emissions. Use of recycled materials: The project demonstrated an approach in which large quantities of recycled material can be used (as high as 100%), though at present a magnesium recycling on a industrial scale does not exist. The project demonstrated that the only possibility to really reduce all emissions produced by the ‘internal combustion engine’ transportation sector is to reduce, by as much as possible, the ‘hidden’ emissions, usually not accounted for by car manufacturers. With this in mind, the project team suggests that the assessment of the impact of any vehicle component should consider the total ‘Cradle-to-Gate’ analysis. The project showed that if a ‘Cradle-to-Gate’ impact factor is made mandatory for any material/solution introduced in a vehicle (re)design, the solutions of the Green Metallurgy process can be competitive. Such a requirement would lead to the replication of the proposed process in the production of larger products such as those required in the construction of aircraft and trains. The process was designed to be viable on an industrial scale. In particular, the mechanics were kept simple by including and assembling parts available on the market. It is therefore easy to replicate. All the products were validated at the demonstration pilot. The demonstrated high scalability of the machinery, its clear environmental benefits, the improvement to the general working conditions, its high marketability and the stability of material costs provided by integrating recycling are all keys for the sustainability and continuation of the project by companies that are involved/interested in manufacturing automotive lightweight components. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).