MoSi2/Al2O3 FGM:: elaboration by tape casting and SHS

MoSi2/Al2O3 functionally graded materials (FGM) with alumina contents varying from 20 to 80 mol% have been fabricated using a combination of tape casting and self-propagating high-temperature synthesis (SHS). Tape casting was used to prepare tapes of different compositions. Square units cut out of tapes with different compositions were stacked in a variety of sequences. After debinding, the green samples were ignited at room temperature. The combustion reactions were conducted under a weak load to enhance the densification of the composition-graded composites. The variation of porosity as a function of the applied pressure and of the thickness of the layers was investigated. The electrical resistivity of the as-obtained FGM varies by more than 10 orders of magnitude across the composite. (C) 2001 Published by Elsevier Science Ltd.