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Thermal Conductivity Characterization of Hafnium Diboride‐Based Ultra‐High‐Temperature Ceramics
Author(s) -
Gasch Matthew,
Johnson Sylvia,
Marschall Jochen
Publication year - 2008
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/j.1551-2916.2008.02364.x
Subject(s) - thermal conductivity , materials science , thermal diffusivity , spark plasma sintering , ceramic , laser flash analysis , atmospheric temperature range , porosity , composite material , sintering , hafnium , grain size , hot pressing , mineralogy , analytical chemistry (journal) , metallurgy , zirconium , thermodynamics , chemistry , physics , chromatography
We evaluated the thermal conductivity of HfB 2 ‐based ultra‐high‐temperature ceramics from laser flash diffusivity measurements in the 25°–600°C temperature range. Commercially available powders were used to prepare HfB 2 composites containing 20 vol% SiC, some including TaSi 2 (5 vol%) and Ir (0.5 or 2 vol%) additions. Samples were consolidated via conventional hot pressing or spark plasma sintering. Processing differences were shown to lead to differences in magnitude and temperature dependence of effective thermal conductivity. We compared results with measured values from heritage materials and analyzed trends using a network model of effective thermal conductivity, incorporating the effects of porosity, grain size, Kapitza resistance, and individual constituent thermal conductivities.