Low-Temperature Processing of ZrB2-ZrC Composites by Reactive Hot Pressing

Rangaraj, Lingappa and Suresha, Siriyara J and Divakar, Canchi and Jayaram, Vikram (2008) Low-Temperature Processing of ZrB2-ZrC Composites by Reactive Hot Pressing. In: Symposium on Materials Behavior - Far from Equilibrium, DEC 15-16, 2006, Bombay.

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Abstract

Dense ZrB2-ZrC and ZrB2-ZrC x∼0.67 composites have been produced by reactive hot pressing (RHP) of stoichiometric and nonstoichiometric mixtures of Zr and B4C powders at 40 MPa and temperatures up to 1600 °C for 30 minutes. The role of Ni addition on reaction kinetics and densification of the composites has been studied. Composites of ∼97 pct relative density (RD) have been produced with the stoichiometric mixture at 1600 °C, while the composite with ∼99 pct RD has been obtained with excess Zr at 1200 °C, suggesting the formation of carbon deficient ZrC x that significantly aids densification by plastic flow and vacancy diffusion mechanism. Stoichiometric and nonstoichiometric composites have a hardness of ∼20 GPa. The grain sizes of ZrB2 and ZrC x∼0.67 are ∼0.6 and 0.4 μm, respectively, which are finer than those reported in the literature.

Item Type:	Conference Paper
Publisher:	The Minerals, Metals & Materials Society
Additional Information:	Copyright of this article belongs to The Minerals, Metals & Materials Society.
Department/Centre:	Division of Chemical Sciences > Materials Research Centre Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	24 Mar 2010 10:18
Last Modified:	19 Sep 2010 05:58
URI:	http://eprints.iisc.ac.in/id/eprint/26503

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