Densification and microstructure development in spark plasma sintered WC–6 wt% $ZrO_2$ nanocomposites

Biswas, Krishanu and Mukhopadhyay, Amartya and Basu, Bikramjit and Chattopadhyay, Kamanio (2007) Densification and microstructure development in spark plasma sintered WC–6 wt% $ZrO_2$ nanocomposites. In: Journal of Materials Research, 22 (6). pp. 1491-1501.

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Abstract

In this paper, we report the results of a transmission electron microscopy investigation on WC–6 wt% $ZrO_2$ nanocomposite, spark plasma sintered at 1300 °C, for varying times of up to 20 min. The primary aim of this work was to understand the evolution of microstructure during such a sintering process. The investigation revealed the presence of nanocrystalline $ZrO_2$ particles (30–50 nm) entrapped within submicron WC grains. In addition, relatively coarser $ZrO_2$ (60–100 nm) particles were observed to be either attached to WC grain boundaries or located at WC triple grain junctions. The evidence of the presence of a small amount of $W_2C$, supposed to have been formed due to sintering reaction between WC and $ZrO_2$, is presented here. Detailed structural investigation indicated that $ZrO_2$ in the spark plasma sintered nanocomposite adopted an orthorhombic crystal structure, and the possible reasons for $o-ZrO_2$ formation are explained. The increase in kinetics of densification due to the addition of $ZrO_2$ is believed to be caused by the enhanced diffusion kinetics in the presence of nonstoichiometric nanocrystalline $ZrO_2$.

Item Type:	Journal Article
Publication:	Journal of Materials Research
Publisher:	Materials Researh Society (MRS)
Additional Information:	Copyright of this article belongs to Materials Research Society (MRS).
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	24 Oct 2007
Last Modified:	19 Sep 2010 04:38
URI:	http://eprints.iisc.ac.in/id/eprint/11668

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