Abstract

The room and elevated temperature flexural strengths were measured for (Hf,Nb,Ta,Ti,Zr)B2–(Hf,Nb,Ta,Ti,Zr)C high-entropy dual-phase ceramics. The fracture of ceramics originated from two distinct flaw populations that were either surface defects introduced during specimen preparation or volume defects introduced during processing. The average strength at room temperature was 638 ± 94 MPa with individual bars strengths as high as ∼800 MPa. At 1800°C, average strength increased to 786 ± 265 MPa with individual bar strengths as high as ∼1050 MPa. Above 1800°C, creep dominated resulting in deformation of the bars without fracture. The fracture mode changed from completely trans granular at room temperature to mixed mode with increasing temperature and then to completely intergranular at 1800°C. The room temperature strength was higher than the reported strengths of the individual constituent phases, which was attributed to fine grain sizes. At elevated temperatures, the increase in strength could be due to the relaxation of stresses in addition to the grain size. To our knowledge, this is the first study reporting the flexural strength of (Hf,Nb,Ta,Ti,Zr)B2–(Hf,Nb,Ta,Ti,Zr)C dual-phase ceramics at elevated temperatures.

Department(s)

Materials Science and Engineering

Publication Status

Full Access

Keywords and Phrases

dual-phase ceramics; flexural strength; intergranular fracture; transgranular fracture

International Standard Serial Number (ISSN)

1551-2916; 0002-7820

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2025 Wiley, All rights reserved.

Publication Date

01 Jan 2025

Download

Full Text Link

Share

 
COinS