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Thermal Properties of (Zr, TM)B 2 Solid Solutions with TM = Ta, Mo, Re, V, and Cr
Author(s) -
McClane Devon L.,
Fahrenholtz William G.,
Hilmas Gregory E.
Publication year - 2015
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.13341
Subject(s) - materials science , tantalum , zirconium , solid solution , thermal conductivity , rietveld refinement , vanadium , analytical chemistry (journal) , molybdenum , lattice constant , sintering , electrical resistivity and conductivity , rhenium , metallurgy , crystal structure , diffraction , crystallography , chemistry , composite material , physics , electrical engineering , chromatography , optics , engineering
The thermal properties were investigated for hot‐pressed zirconium diboride containing solid solution additions of tantalum, molybdenum, rhenium, vanadium, and chromium. The nominal 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 2150°C. 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 25°C ranged from 88 W·(m·K) −1 for nominally pure ZrB 2 down to 28 W·(m·K) −1 for (Zr,Cr)B 2 . Electron contributions to thermal conductivity were calculated from electrical resistivity measurements using the Wiedemann–Franz law. Decreases in phonon and electron conduction correlated with the size of the metallic additive, indicating that changes in atom size in the Zr lattice positions reduced thermal transport.