Fabrication technologies for oxide-oxide ceramic matrix composites based on electrophoretic deposition

Electrophoretic deposition (EPD) was used to fabricate alumina matrix composites with high volume fraction of woven fibre imat (Nextel (TM) 720) reinforcement in a multilayer structure. Colloidal Suspensions of AI,03 nanoparticles in ethanol medium with addition of 4-hydrobezoic acid were used for EPD. Two different techniques were developed for fabrication of Al(2)O(3) matrix/Nextel (TM) 720 fibre composites. The first method is a combination of standard EPD of single fibre mats with a Subsequent lamination procedure to fabricate the multilayered composite. The second method involves the simultaneous infiltration of several (three or more) Nextel (TM) 720 fibre mats by EPD in a tailor-made cell. The composites exhibit a homogeneous matrix microstructure, characterised by a very high particle packing density and relatively low porosity after sintering at 1300 degrees C. The EPD cell allows production of relatively large bodies (10cm diameter). By combination of the inultilayer EPD infiltration and lamination processes developed here, thick ceramic matrix composite components (> 10 mm thickness) can be fabricated, which opens the possibility of greater industrial application of the materials. (c) 2005 Elsevier Ltd. All rights reserved.