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1143 |
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Mechanical modeling of two-phase thermally sprayed abradable coatings |
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Jean-Louis Seichepine / LERMPS - UTBM, France Dieter Sporer / Sulzer Metco (Canada) Inc, Canada Damien Lourtie/ Techspace Aero, Belgique Christian Coddet/ LERMPS, University of Technology of Belfort-Montbeliard, France |
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Abradable seals are used in aerospace applications to control the overtip leakages between the blades of an engine rotor and its static parts. To achieve the combination of the properties required, these seals have been developed with thermally sprayed coatings generally elaborated from a range of two or three phase powder mixtures, resulting in highly heterogeneous composite materials. A good knowledge of the mechanical behaviour of these materials is the first step towards the understanding of the seal performances in working conditions. Finite Element calculations were derived from the analysis of micrographs and allowed to estimate the coefficients of an anisotropic elastic law of behaviour. Several models were investigated in the case of an AlSi-PE (Polyester) coating. As the PE % appeared to be a determinant factor, its influence was quantified ranging from 0% to 100%, using virtual micrographs deduced from the original ones. The computed Young's moduli Ex (in coating's longitudinal direction) were quite consistent, considering the hypotheses made. An empirical relationship giving the variation law of Ex versus the PE % was suggested and applied to predict the modulus Ex of a real coating, which was close to the measured value. This study was funded by the European Commission under the 6th RTD Framework Program (FP6). |