About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Materials Genome, CALPHAD, and a Career over the Span of 20, 50, and 60 Years: An FMD/SMD Symposium in Honor of Zi-Kui Liu
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Presentation Title |
Thermochemical and Thermophysical Properties of Metal Diborides (MB2 | M = Ti, Zr, Nb, Hf, Ta) up to 3150 ˚C |
Author(s) |
Scott J. Mccormack, Stuart Ness, Fox Thrope, Elizabeth Sobalvarro, James Cahil, Gabrella King, Wyatt Du Frane, Joshua Kuntz |
On-Site Speaker (Planned) |
Scott J. Mccormack |
Abstract Scope |
Metal diborides are considered an ultra-high temperature refractory ceramic due to its relatively low reactivity and high melting point. This work will discuss (i) the use of high temperature drop solution calorimetry to measure enthalpies of mixing between the metal diboride components (ZrB2-TaB2), along with (ii) in-situ high temperature X-ray diffraction measurements up to ~3150˚C using a conical nozzle levitator system equipped with a 400W CO2 laser. The enthalpy of mixing data was used to calculate miscibility gaps. The high temperature X-ray diffraction data was used to calculate anisotropic coefficients of thermal expansion. The coefficients were compared amongst the five diborides. It was found that the anisotropy could be related to the atomic displacement parameters of the metal cations. These thermochemical and thermophysical measurements will be critical in developing ultra-high temperature material systems for applications in hypersonic vehicles, nuclear fission/fusion reactors, and spacecraft.
Prepared by LLNL under Contract DE-AC52-07NA27344 |
Proceedings Inclusion? |
Planned: |
Keywords |
High-Temperature Materials, Ceramics, |