Trans Tech Publications, Materials Science Forum, (775-776), p. 562-565, 2014
DOI: 10.4028/www.scientific.net/msf.775-776.562
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This work aimed to develop an alumina composite reinforced with polycrystalline alumina fibers to increase the mechanical properties of the product. A water-based processing was carried out, replacing the use of toxic and flammable organic solvents. The forming technique used was tape casting, which in addition to reliability and low cost, enables to make thin, flat tapes. The parameters for the tape casting process were: gap between the blades of 350 μm and casting speed of 12 cm/min. The process was optimized through a rheological study and alumina suspension with 50 wt.% solids was used. The slurry showed a pseudoplastic behavior and a high value of thixotropy. Several methods for separation and processing of the fibers were tested and a scattering using a specially designed support was the most efficient option. The tapes were thermopressed at 65°C and 30 MPa. The tensile test of green tapes showed a significant increase of the mechanical resistance for fiber-reinforced tapes, which was also dependent on fiber orientation.