Effects of Ti, Y, and Hf Additions on the Thermal Properties of ZrB₂

Abstract

Reactive hot pressing was utilized to synthesize and densify four ZrB2 ceramics with impurity contents low enough to avoid obscuring the effects of dopants on thermal properties. Nominally pure ZrB2 had a thermal conductivity of 141 ± 3 W/m K at 25 °C. Additions of 3 at% of Ti, Y, or Hf decreased the thermal conductivity by 20 %, 30 %, and 40 %, respectively. The thermal conductivity of (Zr,Hf)B2 was similar to ZrB2 synthesized from commercial powders containing the natural abundance of Hf as an impurity. This is the first study to demonstrate that Ti and Y additions decrease the thermal conductivity of ZrB2 2 ceramics and report intrinsic values for thermal conductivity and electrical resistivity of ZrB2 containing transition metal additions. Previous studies were unable to detect these effects because the natural abundance of Hf present masked the effects of these additions.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Electrical resistivity; Solid solution; Thermal conductivity; Ultra high temperature ceramics; Zirconium diboride

International Standard Serial Number (ISSN)

0955-2219

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2020 Elsevier Ltd, All rights reserved.

Publication Date

24 Apr 2020

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