Abstract

The intermediate stage densification kinetics of (Hf, Nb, Ta, Ti, Zr) B2 and (Hf, Nb, Ta, Ti, Zr) C were studied using a Coble creep rate model. (Hf, Nb, Ta, Ti, Zr) B2 was synthesized by boro/carbothermal reduction and (Hf, Nb, Ta, Ti, Zr) C was synthesized by carbothermal reduction. Both ceramics were densified by spark plasma sintering at 1700–1850°C. The activation energies for densification were 575 ± 53 kJ/mol for the high-entropy boride and 646 ± 4 kJ/mol for the high-entropy carbide. The densification mechanisms were grain boundary diffusion for the high-entropy boride and lattice diffusion for the high-entropy carbide. Dissolution of Nb into the high-entropy phase was determined to be the rate limiting mechanism for densification of both the carbide and the boride.

Department(s)

Materials Science and Engineering

Comments

Office of Naval Research, Grant N00014-21-1-2515

Keywords and Phrases

Borides; Carbides; Densification kinetics; High entropy; SPS

International Standard Serial Number (ISSN)

1873-619X; 0955-2219

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2025 Elsevier, All rights reserved.

Publication Date

01 May 2025

Share

 
COinS