The ExoMet project focused on novel liquid-metal engineering of Al- and Mg-based alloys and metal-matrix nanocomposites (or MMNCs). This was achieved by the application of external physical fields which significantly influence the microstructure and properties of these materials. The fields were meant to promote even mixing before solidification of the metals. Three types of external fields were explored: electromagnetic, ultrasonic, and intensive liquid shearing.
The project had several objectives. Mainly, the goal was to develop new technologies based on tailored electromagnetic fields, power ultrasound and intensive liquid shearing, which could be used in both shape castings and wrought billets. Various casting processes could be influenced this way, including low- and high-pressure die casting, sand casting, differential-pressure casting, twin-roll casting and ultrasound-assisted casting. The process was supported by computer modelling and development of associated software. The improved castability of light Al and Mg alloys aimed to reduce both production and life-cycle costs for the resultant components. The techniques were then prototyped for industrial use in automotive powertrain and chassis applications, aircraft and aero-engine structures, space satellites and rockets, and high-strength high-conductivity aluminium electrical cabling.
In the end, significant enhancement in properties of the metals was achieved. The foreseen improvements were 25–50% increases in tensile strength and ductility, operating temperatures in the range 300–350°C, as well as other benefits for fatigue properties, fracture toughness, coefficient of thermal expansion and electrical conductivity. In addition to better properties, implementing these alloys in practice would come with a lower environmental impact. Not only do the external-field processes have relatively low energy levels (in kWh) and are efficient in their energy conversion, they could also lead to at least 30% weight savings in vehicle components, and subsequent decrease in fuel consumption. The use of raw materials is also significantly reduced with the newly developed techniques; the project aimed for 20% reduction in scrap-rate in the manufacturing process.
| Key partners
Co-ordinated by the European Space Agency (ESA), 27 partners:
ALD Vacuum Technologies GmbH (DE), AVIO S.p.A (IT), Brabant Alucast International B.V. (NL), Brunel University (GB), Calcom ESI (CH), Centro Ricerche Fiat S.C.p.A. (IT), EADS Deutschland GmbH (DE), European SPace Agency – Physical Science Unit (NL), GIE EADS CCR (FR), Grenoble Institute of Technology (FR), IMDEA-Materials (ES), INASMET Tecnalia San Sebastián (ES), London & Scandinavian Metallurgical Co. Ltd. (GB), Norsk Hydro ASA (NO), Norwegian University of Science and Technology (NO), Politecnico di Torino (IT), PRECER AB (SE), Research Institute for Solid State Physics and Optics of the Hungarian Academy of Sciences (HU), Steinbeis-Transferzentrum Advanced Risk Technologies (R-Tech) (DE), The University of Queensland (AU), Tomsk State University (RU), Université de Rouen, Sciences et Techniques (FR), University of Greenwich (GB), University of Manchester (GB), Volvo Technology Corporation (SE), University of Birmingham (GB).