Objective In the present project it is intended to develop novel multi-element diffusion coatings resistant to different aggressive environments at high temperatures using fluidized bed and plasma fluidized bed technology, and also to develop the tools and procedures for predicting and evaluating the thermodynamic and kinetic parameters that control multi-element diffusion treatments.The thermochemical/thermodynamic calculation using the CHEMSAGE software package indicated that by using the appropriate reacting substances Cr/Al and small amounts of rare earth elements, Hf and to a very minor extent Yt, can be deposited on Fe and Ni alloys. For the hard coatings TiN and TiB2 also appear to be feasible under certain conditions of temperature and reacting substances. Two reactors, a fluidized bed reactor (FBR) and a plasma fluidized bed reactor (PFBR) and all the auxiliary units for their operation and control were designed and constructed. Using the two reactors and by varying the temperature, time and the chemical reactants fed in the reactors, the following coatings were obtained. In the FBR: - A CrAlYt coating of approximately 150 µm thickness on Fe alloy - A Cr(Hf) carbide coating of approximately 25 µm thickness on tool steel. The high temperature CrAlYt coating and the Cr(Hf) carbide hard coating were of acceptable thickness, showed very good adhesion and uniformity and satisfactory properties. A Fe alloy with the CrAlYt coating showed improved thermal fatigue properties and the Cr(Hf) carbide layer showed Vickers microhardness values in the range of 1531 - 1921. Both these layers could be of commercial interest as they are easy to obtain in the FBR. In the PFBR Ti and N elements were deposited on steel substrate. This method did not lead to the formation of continuous layer and certain measures are proposed in order to achieve this objective. The numerical Model developed is operational and can be applied to Plasma spouted bed reactor.In fluidization, a bed of finally divided particles is made to behave like a liquid by a moving gas fed upwards through the bed. This technique is cost effective easily controlled and flexible enough and allows to obtain improved multi-element diffusion coatings resistant to aggressive environments. The new powerful computer package ChemSage will be used to analyse and predict the complex equilibrium phenomena taking place during diffusion treatments, so as to optimise the simultaneous diffusion of elements such as : B, C, N, with Ti and Hf and Al, Cr, with Yt, La, Ce. The substrate materials will be Fe and Ni alloys. The high temperature corrosion in S, halogen containing atmospheres, oil ash corrosion, thermal fatigue erosion and wear properties, as well as full characterization by X-rays diffraction and Electron Microscopy, of the obtained coatings will be carried out. Fields of science natural scienceschemical sciencesinorganic chemistryinorganic compoundsnatural sciencesphysical sciencesopticsmicroscopyelectron microscopynatural scienceschemical sciencesinorganic chemistrypost-transition metalsengineering and technologymaterials engineeringcoating and filmsnatural scienceschemical sciencesinorganic chemistryhalogens Programme(s) FP3-CRAFT - Specific programme of research and technological development in the field of industrial and materials technologies - CRAFT -, 1990-1994 Topic(s) Data not available Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator A. Forulis & Sons S.A. EU contribution No data Address 187,Larissis Street 38334 Volos Greece See on map Total cost No data Participants (8) Sort alphabetically Sort by EU Contribution Expand all Collapse all AACHEN UNIVERSITY OF TECHNOLOGY Germany EU contribution No data Address Kopernikusstraße 14 52056 AACHEN See on map Total cost No data Aristotle University of Thessaloniki Greece EU contribution No data Address Egnatia Street 54006 Thessaloniki See on map Total cost No data CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE France EU contribution No data Address Avenue de Villeneuve 52 66860 PERPIGNAN See on map Total cost No data Elvem S. Kopanos and Co Greece EU contribution No data Address 16-18,Samou Street 10438 Athens See on map Total cost No data Fluidbi France EU contribution No data Address 3 allée de l'Aventure 77184 Emerainville See on map Total cost No data GTT - Technologies Germany EU contribution No data Address Kaiserstraße 100 52134 Herzogenrath See on map Total cost No data Schwing Verfahrenstechnik GmbH Germany EU contribution No data Address Oderstraße 7 47506 Neukirchen See on map Total cost No data University of Thessalia Greece EU contribution No data Address Pedion Areos Athinon Avenue 38334 Volos See on map Total cost No data
