MoSi2/Al2O3 FGM: elaboration by tape casting and SHS

MoSi2/Al2O3 functionally graded materials (FGM) with alumina contents varyi ng from 20 to 80 mol% have been fabricated using a combination of tape cast ing and self-propagating high-temperature synthesis (SHS). Tape casting was used to prepare tapes of different compositions. Square units cut out of t apes with different compositions were stacked in a variety of sequences. Af ter debinding, the green samples were ignited at room temperature. The comb ustion reactions were conducted under a weak load to enhance the densificat ion of the composition-graded composites. The variation of porosity as a fu nction of the applied pressure and of the thickness of the layers was inves tigated. The electrical resistivity of the as-obtained FGM varies by more t han 10 orders of magnitude across the composite. (C) 2001 Published by Else vier Science Ltd.