Solid-State Formation Mechanisms of Core-Shell Microstructures in (Zr,Ta)B₂ Ceramics

Abstract

Transition metal diborides with core-shell microstructures have demonstrated excellent mechanical properties at elevated temperatures. Previous studies concluded that core-shell microstructures were formed by liquid-assisted mass transport mechanisms, but in this study, we propose a solid-state formation mechanism for core-shell microstructures in (Zr,Ta)B2 ceramics produced by reaction hot pressing and in ZrB2-TaB2 diffusion couples. Diffusion couple experiments demonstrated that core-shell microstructures developed as a result of Ta diffusion along ZrB2 grain boundaries, which occurred concurrently with lattice diffusion of Ta into ZrB2. These findings suggest that with optimization of batching and processing parameters, core-shell diboride materials may be formed through solid-state processes rather than liquid-assisted processes, which could assist in raising the upper temperature limits of use for these materials.

Department(s)

Materials Science and Engineering

Publication Status

Early View: Online Version of Record before inclusion in an issue

Comments

This work was funded by Honeywell Federal Manufacturing and Technologies through contract number N000335755.

International Standard Serial Number (ISSN)

1551-2916; 0002-7820

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2022 American Ceramic Society, All rights reserved.

Publication Date

01 Jan 2022

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