Thermal Properties of (Zr, TM)B₂ Solid Solutions with TM = Ta, Mo, Re, V, and Cr
The thermal propertieswere investigated for hot-pressed zirconium diboride containing solid solution additions of tantalum, molybdenum, rhenium, vanadium, and chromium. Thenominal additions were equivalent to 3 at.% of each metal with respect to zirconium. Using 0.5 wt% carbon as a sintering aid, powders were hot-pressed to near full density at 2150C. Rietveld refinement of X-ray diffraction data was used to measure lattice parameters and to ensure that the additives formed solid solutions. Thermal conductivities were calculated from measured thermal diffusivities and temperature-dependent values for density and heat capacity. Thermal conductivities at 25⁰C ranged from 88 W·(m·K)-1 for nominally pure ZrB2 down to 28 W·(m·K)-1 for (Zr,Cr)B2. Electron contributions to thermal conductivity were calculated from electrical resistivity measurements using theWiedemann-Franz law. Decreases in phonon and electron conduction correlated with thesize ofthemetallic additive, indicating that changes in atom size in theZr lattice positions reduced thermal transport.
D. L. McClane et al., "Thermal Properties of (Zr, TM)B₂ Solid Solutions with TM = Ta, Mo, Re, V, and Cr," Journal of the American Ceramic Society, vol. 98, no. 2, pp. 637-644, Blackwell Publishing Inc., Dec 2014.
The definitive version is available at https://doi.org/10.1111/jace.13341
Materials Science and Engineering
Keywords and Phrases
Additives; Rietveld refinement; Sintering; Solid solutions; Specific heat; Thermodynamic properties; X ray diffraction; Zirconium; Electrical resistivity measurements; Electron conduction; Metallic additives; Temperature dependent; Thermal transport; Wiedemann-Franz law
International Standard Serial Number (ISSN)
Article - Journal
© 2014 Blackwell Publishing Inc., All rights reserved.
01 Dec 2014