Pressureless Sintering of Zirconium Diboride: Particle Size and Additive Effects
Zirconium diboride (ZrB2) was densified by pressureless sintering using <4-wt% boron carbide and/or carbon as sintering aids. As-received ZrB2 with an average particle size of~2 μm could be sintered to~100% density at 1900⁰C using a combination of boron carbide and carbon to react with and remove the surface oxide impurities. Even though particle size reduction increased the oxygen content of the powders from~0.9 wt% for the as-received powder to~2.0 wt%, the reduction in particle size enhanced the sinterability of the powder. Attrition-milled ZrB2 with an average particle size of <0.5 μm was sintered to nearly full density at 1850⁰C using either boron carbide or a combination of boride carbide and carbon. Regardless of the starting particle size, densification of ZrB2 was not possible without the removal of oxygen-based impurities on the particle surfaces by a chemical reaction.
W. Fahrenholtz et al., "Pressureless Sintering of Zirconium Diboride: Particle Size and Additive Effects," Journal of the American Ceramic Society, vol. 91, no. 5, pp. 1398-1404, Wiley-Blackwell, May 2008.
The definitive version is available at http://dx.doi.org/10.1111/j.1551-2916.2007.02169.x
Materials Science and Engineering
Keywords and Phrases
Particle size reduction; Pressureless sintering; Sintering aids; Additives; Boron carbide; Densification; Impurities; Particle size; Sintering; Zirconium compounds
International Standard Serial Number (ISSN)
Article - Journal
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