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1501 |
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Wednesday, June 04, 2008, Room 08 3:40 PM Ceramics Coatings for wear resistance and high temperature applications |
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Three-dimensional simulation of porosity in plasma sprayed alumina using microtomography and electrochemical impedance spectrometry for finite element modeling of properties
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Michel Jeandin* / ECOLE DES MINES DE PARIS
/C2P- Competence Center for spray Processing, FRANCE O. Amsellem / Ecole des Mines de Paris - ParisTech, Centre des Matériaux (CNRS 7633), Competence Center for spray Processing (C2P), France K. Madi/ Ecole des Mines de Paris - ParisTech, Centre des Matériaux (CNRS 7633), France F. Borit/ Ecole des Mines de Paris - ParisTech, Centre des Matériaux (CNRS 7633), Competence Center for spray Processing (C2P), France D. Jeulin/ Ecole des Mines de Paris - ParisTech, Centre des Matériaux (CNRS 7633), France V. Guipont/ Ecole des Mines de Paris - ParisTech, Centre des Matériaux (CNRS 7633), Competence Center for spray Processing (C2P), France M. Jeandin/ Ecole des Mines de Paris - ParisTech, Centre des Matériaux (CNRS 7633), Competence Center for spray Processing (C2P), France Elodie Boller/ ID19 Topography & Microtomography Group, European Synchrotron Facility, France F. Pauchet/ Schlumberger, Riboud Product Center, France |
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Moving from a 2-dimensional to a 3-dimensional approach to microstructure and properties has been expected eagerly for a long while to result in a dramatic increase in the knowledge of thermally-sprayed processes and coatings. To meet these expectations, in the present work, microtomography and electrochemical impedance spectroscopy (EIS) were carried out to simulate the microstructure of plasma-sprayed alumina. As-sprayed and excimer laser-processed deposits were studied. Some unexpected but relevant results, e.g. regarding pore orientation in the coatings, could be obtained. EIS simulation led to the establishing of an electrical circuit equivalent to the microstructure which simulated the insulating properties as a function of interfaces and pore interconnection. The latter was studied by microtomography. From this 3-dimensional simulation, a finite element analysis of thermo-mechanical and electrical properties was developed and compared to experimental measurements. Using this approach to microstructure and properties, excimer laser surface processing was shown to be an innovative process to modify insulating characteristics of plasma-sprayed alumina. |