Measurement of the melting temperature of ZrB2 as determined by laser heating and spectrometric analysis. Issue 6 (1st February 2021)

• Record Type: Journal Article
• Authors: Stanfield, Austin D.; Manara, Dario; Robba, Davide; Hilmas, Gregory E.; Fahrenholtz, William G.
• Is Part Of: Journal of the American Ceramic Society. Volume 104:Issue 6(2021)
• Page Start: 2780
• Page End: 2787
• Publication Date: 2021-02-01
• Subjects: borides -- optical materials/properties -- phase transition -- thermal analysis -- ultra‐high temperature ceramics; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.17634
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: 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 T m 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.