Processing and Mechanical Properties of Hot-Pressed Zirconium Diboride - Zirconium Carbide Ceramics


ZrB2 was mixed with 0.5 wt% carbon and up to 10 vol% ZrC and densified by hot-pressing at 2000 °C. All compositions were > 99.8% dense following hot-pressing. The dense ceramics contained 1-1.5 vol% less ZrC than the nominal ZrC addition and had between 0.5 and 1 vol% residual carbon. Grain sizes for the ZrB2 phase decreased from 10.1 µm for 2.5 vol% ZrC to 4.2 µm for 10 vol% ZrC, while the ZrC cluster size increased from 1.3 µm to 2.2 µm over the same composition range. Elastic modulus was ~505 GPa and toughness was ~2.6 MPa·m½ for all compositions. Vickers hardness increased from 14.1 to 15.3 GPa as ZrC increased from 2.5 to 10 vol%. Flexure strength increased from 395 MPa for 2.5 vol% ZrC to 615 MPa for 10 vol% ZrC. Griffith-type analysis suggests ZrB2 grain pullout from machining as the strength limiting flaw for all compositions.


Materials Science and Engineering


Research at Missouri S&T was supported by the High Temperature Aerospace Materials Program (Dr. Ali Sayir, program manager) at the Air Force Office of Scientific Research through grant FA9550-09-1-0168.

Keywords and Phrases

Hot-Pressing; Mechanical Properties; Zirconium Carbide; Zirconium Diboride

International Standard Serial Number (ISSN)

1873-619X; 0955-2219

Document Type

Article - Journal

Document Version


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Publication Date

01 Sep 2022