Infiltration of a 3-D Fabric for the Production of SiC/SiC Composites by Means of Electrophoretic Deposition Saša Novak 1,a , Katja König 1,b , Aljaž Ivekovič 1,c , Aldo R. Boccaccini 2,d 1 Department for Nanostructured Materials, Jožef Stefan Institute, Ljubljana, Slovenia 2 Department of Materials, Imperial College London, London, UK a sasa.novak@ijs.si, b katja.konig@ijs.si, c aljaz.ivekovic@ijs.si, d a.boccaccini@imperial.ac.uk Keywords: electrophoretic infiltration, SiC, fibres, composite  Electrophoretic deposition (EPD) was used to infiltrate 2D and 3D SiC fabrics with SiC submicron particles with the aim to verify the potential of the technique for the fabrication of dense SiC/SiC composites. Bulk SiC deposits were first prepared from aqueous suspensions with different dispersants using cathodic and anodic deposition. The most suitable composition of the suspensions and the conditions for the infiltration were determined on the basis of the analysis of green parts formed. Using a specially designed EPD cell a relatively high packing density of SiC particles in infiltrated 2D and 3D SiC-fiber fabrics was achieved.  Due to their ability to resist extreme conditions, SiC-based composites are recognized as promising materials for structural parts of future fusion reactors. Namely, the use of continuous SiC-fiber reinforced SiC composite (SiC/SiC) for the blanket structural component could lead to a significant increase in the maximum operating temperature. Moreover, the material would not decay under neutron irradiation to produce long-lived radioactive waste. [1,2] Insufficient hermeticity and swelling during application and various technological obstacles, however, represent serious issues that limit the real potential of SiC-based composites in this application. One key issue is related to the feasibility of achieving full infiltration of the SiC-fibre fabric with a low-activation matrix material to be able to produce fully dense composites [3,4]. Presently known techniques used for the infiltration of SiC-fibre woven fabrics with a SiC- matrix material involve chemical vapour infiltration (CVI) and polymer infiltration and pyrolysis (PIP) which however result in incomplete filling of the gaps between the fibres in the tows. By filling approximately one third of the inter-bundle voids with SiC powder before CVI, less than 10 % porosity could be achieved; however, this is still unacceptably high [5]. Further attempts have been based on using ceramic routes (e.g. NITE process), where the fiber-fabric is first infiltrated with a ceramic slurry and densified by a pressure-assisted liquid-phase sintering of the SiC matrix using Al 2 O 3 and Y 2 O 3 as the sintering aids at high temperature [6]. In the last decades electrophoretic deposition (EPD) has been shown to be a fast and efficient technique to prepare ceramic materials of different geometry and complexity [7-10], including fibre reinforced ceramic composites [10. 11]. EPD has also been applied to fabricate of SiC/SiC composites [12-14] by infiltration of 2D fibre fabrics with non-aqueous SiC suspensions. In this work we aimed to verify the potential of the EPD technique for infiltration of 2D and 3D SiC-fibre fabrics with aqueous SiC particle suspensions in order to achieve the highest possible green and sintered densities of the continuous SiC-fibre reinforced SiC composite for fusion reactor applications.  Aqueous suspensions with solids content up to 60 wt.% were prepared from SiC BF12 powder (H. Starck, Germany) of average particle size 0.5 μm. The suspensions were homogenised using strong Key Engineering Materials Vol. 412 (2009) pp 237-242 online at http://www.scientific.net © (2009) Trans Tech Publications, Switzerland Online available since 2009/Jun/15 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of the publisher: Trans Tech Publications Ltd, Switzerland, www.ttp.net. (ID: 193.2.4.4-08/07/09,21:59:37)