Thermal Conductivity of Hot-Pressed ZrB2-ZrC Ceramics
Abstract
The Thermal Conductivity of ZrB2 with 0–10 Vol.% ZrC Was Studied from 25 to 2000 °C. the ZrB2-ZrC Ceramics Were Prepared by Attrition Milling the Starting Powders and Adding 0.5 Wt.% C as a Sintering Aid. the Ceramics Were Hot-Pressed to Full Density at 1900 °C for 30 Min in a Flowing Ar Atmosphere. the Ceramics Contained Graphitic Carbon as a Secondary Phase, with ZrB2 and ZrC Grain Sizes of Approx. 3.5 and 1.5 Μm, Respectively. at Room Temperature, Thermal Conductivity Was 75 W/m·K for Monolithic ZrB2, Increasing to 79 W/m·K for 2.5 Vol.% ZrC, and Decreasing to 72 W/m·K for 10 Vol.% ZrC. at 2000 °C, Thermal Conductivity Was 72 W/m·K for ZrB2, Decreasing to 69 W/m·K for 10 Vol.% ZrC. Electrical Resistivity Behavior Was Similar to Thermal Conductivity, Decreasing with the Addition of ZrC Up to 2.5 Vol.% (9.9 µΩ·cm at 25 °C), Then Increasing with Further ZrC Additions. the Increase in Thermal Conductivity with ZrC Addition Up to 2.5 Vol.% Was the Result of Preferential Segregation of W from the ZrB2 Phase to the ZrC Phase. the Reduction in Thermal Conductivity with Greater ZrC Additions Was Due to the Lower Thermal Conductivity of ZrC.
Recommended Citation
E. W. Neuman et al., "Thermal Conductivity of Hot-Pressed ZrB2-ZrC Ceramics," Materialia, vol. 26, article no. 101638, Elsevier, Dec 2022.
The definitive version is available at https://doi.org/10.1016/j.mtla.2022.101638
Department(s)
Materials Science and Engineering
Keywords and Phrases
Electrical resistivity; Thermal conductivity; Zirconium carbide; Zirconium diboride
International Standard Serial Number (ISSN)
2589-1529
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2023 Elsevier, All rights reserved.
Publication Date
01 Dec 2022
Comments
National Science Foundation, Grant DMR-0906584