Rakshit, J and Das, P K (2000) Optimization of time-temperature schedule for nitridation of silicon compact on the basis of silicon and nitrogen reaction kinetics. Bulletin of Materials Science, 23 (4). 249 -253. ISSN 0250-4707

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Abstract

A time-temperature schedule for formation of silicon-nitride by direct nitridation of silicon compact was optimized by kinetic study of the reaction, 3Si + 2N(2) = Si3N4 at four different temperatures (1250 degrees C, 1300 degrees C, 1350 degrees C and 1400 degrees C). From kinetic study, three different temperature schedules were selected each of duration 20 h in the temperature range 1250 degrees-1450 degrees C, for complete nitridation. Theoretically full nitridation (100% i.e. 66.7% weight gain) was not achieved in the product having no unreacted silicon in the matrix, because impurities in Si powder and loss of material during nitridation would result in 5-10% reduction of weight gain. Green compact of density < 66% was fully nitrided by any one of the three schedules. For compact of density > 66%, the nitridation schedule was maneuvered for complete nitridation. Iron promotes nitridation reaction. Higher weight loss during nitridation of iron doped compact is the main cause of lower nitridation gain compared to undoped compact in the same firing schedule, Iron also enhances the amount of beta-Si3N4 phase by formation of low melting FeSix phase.

Item Type:	Article
Uncontrolled Keywords:	reaction sintered silicon nitride; nitridation; reaction kinetics
Subjects:	UNSPECIFIED
Divisions:	UNSPECIFIED
Depositing User:	Mrs Chandana Patra
Date Deposited:	08 Feb 2012 11:00
Last Modified:	06 Feb 2015 10:44
URI:	http://cgcri.csircentral.net/id/eprint/702

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