Duration of the project:
Jožef Stefan Institute
University of Primorska Faculty of Health Sciences
R&D Center for Nanotechnologies in the Field of Magnetic Materials and Composites
Principal investigator / researcher:
Ingrid Milošev (SICRIS)
In the last decade the European automobile industry has more than doubled the average amount of aluminium used in passenger cars and the trend in increasing. European Union legislation sets mandatory emission reduction targets for new cars. Europe is to become a highly energy efficient, low carbon economy. Road transport alone contributes about one fifth of the EU’s total emissions of carbon dioxide, the main greenhouse gas. The reduction of emissions from a range of modes of transport could be achieved partially by increased use of light alloys and consequent reduction in weight and fuel consumption. Among light materials, aluminium and its alloys have the highest potential and will be the subject of this project. These materials exhibit good strength to weight ratio, good ductility and strength and are relatively easy to fabricate by forming, machining, or welding. Their versatile applications are met in almost every industrial and commercial segment. With increasing mobility in modern era the transport industry has a growing capacity. The increase use of light materials will demand the increased use of their protection as well. This is especially important due to restriction of use of toxic chromate coatings which have been applied with great success for decades for protection of Al alloys. The main goal of the project it to develop the coatings to withstand severe conditions for various Al alloys in transport industry applications, including high salt and sulphur content, low and elevated temperatures and bacterial attack.
Corrosion protection of aluminium alloys is related to the protection of intermetallics in the alloys, as these represent initiation process for corrosion process. Most relevant for transport industry are Al alloys from series 2xxx, 5xxx, 6xxx and 7xxx which contain intermetallics rich in Cu, Mg, Si and Zn. Two main research routes will be opened: protection by sol-gel coatings and by conversion coatings. In both routes green chemical approach will be applied with the use of nontoxic chemicals. The synthesis of coatings will be the main innovative area within the project. The effectiveness of corrosion protection will be studied using electrochemical methods in solutions simulating ambient environment. Coatings selected for their high effectiveness will be further investigated under the conditions of microbial induced corrosion. Most common types of bacteria associated with metals in terrestrial and aquatic habitats are sulphatereducing bacteria, sulphuroxidising bacteria, iron oxidising/reducing bacteria, manganese oxidising bacteria, and bacteria secreting organic acids and slime. Further, standard laboratory and field testing will be carried out under the condition relevant for applications. Field testing will be carried out in collaboration with Slovenian company Pipistrel, world recognized manufacturer of light aircrafts. Both types of testing will importantly upgrade the electrochemical studies of the developed coatings and give the project additional perspective for further applications. Although this is basic research project these activities position it high at the technology readiness level as it will demonstrate performance relevant in end to end environment.
The project offers the integral approach and solution of the identified problems development and synthesis of coatings for aluminium alloys to withstand severe conditions in transport industry. Proposed research will enrich the scientific community with new important results. Interdisciplinarity of the project will broaden the scientific methodology which could not be developed within individual scientific field – chemistry, materials science and microbiology. Consequently, each of these scientific fields will gain and deepen the knowledge of its basic and applied research for which all required instrumentation is available. We can therefore expect that the results of the proposed project will substantially contribute to solving the important problems related to the corrosion of light alloys in transport industry.
»The authors acknowledge the project J1-6734 Lightweight alloys based on aluminium as materials with increasing potential in transport industry was finacially supported by the Slovenian Research Agency.«