Measurement of the Melting Temperature of ZrB₂ as Determined by Laser Heating and Spectrometric Analysis
The melting temperatures of two different ZrB2 ceramics were studied using laser induced melting. ZrB2 having a low Hf content, produced by reaction hot pressing, had a melting temperature of 3546 K and a commercial grade ZrB2 had a melting temperature of 3553 K. Uncertainty of the temperature measurements was 1% of the absolute temperature, or ~35 K for both materials based upon 2-sigma and a 95% confidence interval. While these values were consistent with the previously reported ZrB2 melting temperature of 3518 K, this study was able to measure Tm with less uncertainty than previous studies (± 45 K). Furthermore, this study assessed the effect of Hf content on melting temperature, finding that melting temperature did not change significantly for hafnium contents of 1.75 to 0.01 at%. This study also measured a normal spectral emissivity of 0.34 for ZrB2 at 3000 K. The emissivity decreased to 0.28 at the melting temperature, then, stabilized at 0.30 in a liquid phase.
A. D. Stanfield et al., "Measurement of the Melting Temperature of ZrB₂ as Determined by Laser Heating and Spectrometric Analysis," Journal of the American Ceramic Society, vol. 104, no. 6, pp. 2780 - 2787, Wiley, Jun 2021.
The definitive version is available at https://doi.org/10.1111/jace.17634
Materials Science and Engineering
Keywords and Phrases
Borides; Optical Materials/Properties; Phase Transition; Thermal Analysis; Ultra-High Temperature Ceramics
International Standard Serial Number (ISSN)
Article - Journal
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01 Jun 2021