Biswas, Sampad Kumar and Riley, FL (2003) Gas pressure sintering of silicon nitride powder coated with Al(2)O(3) and TiO(2). Journal of the American Ceramic Society, 86 (2). pp. 212-216. ISSN 0002-7820

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Abstract

Gas pressure sintering kinetics of silicon nitride powder coated with 10 wt% (9:1) Al(2)O(3) and TiO(2) have been studied at 1850degreesC with a pressure schedule of 0.3 MPa in the first stage and I MPa in the second stage. The rates have been analyzed with a liquid-phase sintering model. Diffusion-controlled intermediate-stage kinetics have been observed. The role of second-step pressurization with nitrogen and argon has been determined by monitoring the kinetics. Pressurization at an earlier stage (similar to90% relative density) reduces the densification rate but produces a denser material at the final stage. Although final density is greater, a porous surface layer forms on samples sintered with argon pressurization at the second stage. No such porous layer is formed in the case of pressurization with nitrogen. The mechanism of the intermediate-stage kinetics has been discussed with respect to the nature of the product analyzed by XRD after sintering.

Item Type:	Article
Uncontrolled Keywords:	Sinter/sintering; Silicon nitride; Aluminum oxide
Subjects:	Engineering Materials
Divisions:	UNSPECIFIED
Depositing User:	Subhra Lahiri
Date Deposited:	14 Feb 2012 11:53
Last Modified:	14 Feb 2012 11:53
URI:	http://cgcri.csircentral.net/id/eprint/827

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