Improved Oxidation Resistance of Zirconium Diboride by Tungsten Carbide Additions

Abstract

The effect of tungsten carbide (WC) additions on the oxidation resistance of zirconium diboride (ZrB2) was studied. Zirconium diboride ceramics, nominally pure and with the addition of 4 mol% WC, were densified by pressureless sintering. During densification, the WC that was added to the ceramic dissolved into the ZrB2 matrix, forming a solid solution. Oxidation behavior was evaluated using thermal gravimetric analysis up to 1500°C and isothermal furnace oxidation at 1500° and 1600°C. The WC additions reduced both the weight gain and the oxide scale thickness. After oxidation at 1600°C for 3 h, the mass gain decreased from 22 mg/cm2 for nominally pure ZrB2 to 8 mg/cm2 for the WC-containing ceramic. Analysis showed that the WC additions improved the oxidation resistance of ZrB2 by promoting densification of the zirconia scale formed during oxidation through liquid-phase sintering.

Department(s)

Materials Science and Engineering

Sponsor(s)

Air Force Research Laboratory (Wright-Patterson Air Force Base, Ohio)

Keywords and Phrases

Oxidation Resistance; Tungsten Carbide; Zirconium Diboride

International Standard Serial Number (ISSN)

0002-7820; 1551-2916

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2008 John Wiley & Sons, All rights reserved.

Publication Date

01 Oct 2008

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