Preparation of Si3N4-SiC composites by microwave route

Panneerselvam, M and Rao, KJ (2002) Preparation of Si3N4-SiC composites by microwave route. In: Bulletin of Materials Science, 25 (7). pp. 593-598.

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Abstract

Si3N4-SiC composites have been microwave sintered using beta-Si3N4 and beta-SiC as starting materials. Si3N4 rich compositions (95 and 90 vol.% Si3N4) have been sintered above 96% of theoretical density without using any sintering additives in 40 min. A monotonic decrease in relative density is observed with increase in SiC proportion in the composite. Decrease in relative density has manifested in the reduction of fracture toughness and microhardness values of the composite with increase in SiC content although the good sintering of matrix Si3N4 limits the decrease of fracture toughness. Highest value of fracture toughness of 6.1 MPa m(1/2) is observed in 10 vol.% SiC composite. Crack propagation appears to be transgranular in the Si3N4 matrix and the toughening of the composites is through crack deflection around hard SiC particles in addition to its debonding from the matrix.

Item Type:	Journal Article
Publication:	Bulletin of Materials Science
Publisher:	Indian Academy of sciences
Additional Information:	copyright of this article belongs to Indian Academy of sciences.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	18 Nov 2009 10:49
Last Modified:	19 Sep 2010 04:53
URI:	http://eprints.iisc.ac.in/id/eprint/16719

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