Elevated Temperature Thermal Properties of ZrB₂-B₄C Ceramics

Abstract

The elevated temperature thermal properties of zirconium diboride ceramics containing boron carbide additions of up to 15 vol% were investigated using a combined experimental and modeling approach. The addition of B4C led to a decrease in the ZrB2 grain size from 22 µm for nominally pure ZrB2 to 5.4 µm for ZrB2 containing 15 vol% B4C. The measured room temperature thermal conductivity decreased from 93 W/m·K for nominally pure ZrB2 to 80 W/m·K for ZrB2 containing 15 vol% B4C. The thermal conductivity also decreased as temperature increased. For nominally pure ZrB2, the thermal conductivity was 67 W/m·K at 2000 °C compared to 55 W/m·K for ZrB2 containing 15 vol% B4C. A model was developed to describe the effects of grain size and the second phase additions on thermal conductivity from room temperature to 2000 °C. Differences between model predictions and measured values were less than 2 W/m·K at 25 °C for nominally pure ZrB2 and less than 6 W/m·K when 15 vol% B4C was added.

Department(s)

Materials Science and Engineering

Comments

The authors thank the Advanced Materials Characterization Laboratory at Missouri S&T for SEM. 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

Boron Carbide; Thermal Conductivity; 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

© 2022 Elsevier, All rights reserved.

Publication Date

01 Aug 2022

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