Thermal Properties of ZrB₂-TiB₂ Solid Solutions

Abstract

Zirconium diboride ceramics were prepared with additions of up to 50 vol.% TiB2. The resulting (Zr,Ti)B2 ceramics formed complete solid solutions based on x-ray diffraction. The addition of TiB2 resulted in grain size decreasing from 22 μm for nominally pure ZrB2 to 7 μm for ZrB2-50 vol.% TiB2. The thermal conductivity at 25°C ranged from 93 W/m⋅K for nominally pure ZrB2 to 58 W/m⋅K for ZrB2-50 vol.% TiB2. Thermal conductivity was as high as 67 W/m⋅K for nominally pure ZrB2 at 2000°C, but dropped to 59 W/m K with the addition of 50 vol.% TiB2. Electrical resistivity measurements were used to calculate the electron contribution to thermal conductivity, which was 76 W/m⋅K for nominally pure ZrB2 decreasing to 57 W/m⋅K when 50 vol.% TiB2 was added. The phonon contribution to thermal conductivity did not change significantly for ≤ 10 vol.% TiB2. Additions of ≥ 25 vol.% TiB2 reduced the phonon contribution to nearly zero for all temperatures.

Department(s)

Materials Science and Engineering

Comments

This work was financially supported by the High Temperature Aerospace Materials Program (Ali Sayir Program Manager) in the U.S. Air Force Office of Scientific Research on grant number FA9550-09-1-0168.

Keywords and Phrases

Solid Solution; Thermal Conductivity; Titanium Diboride; Zirconium Diboride

International Standard Serial Number (ISSN)

1873-619X; 0955-2219

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2021 Elsevier, All rights reserved.

Publication Date

01 Dec 2021

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