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Materials Science and Engineering

Materials Science and Engineering Faculty Research & Creative Works

2022

Mechanical properties

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Full-Text Articles in Engineering

Processing And Mechanical Properties Of Hot-Pressed Zirconium Diboride – Zirconium Carbide Ceramics, Eric W. Neuman, William Fahrenholtz, Gregory E. Hilmas Sep 2022

Processing And Mechanical Properties Of Hot-Pressed Zirconium Diboride – Zirconium Carbide Ceramics, Eric W. Neuman, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

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. …


Room-Temperature Mechanical Properties Of A High-Entropy Diboride, Alec C. Murchie, Jeremy Lee Watts, William Fahrenholtz, Gregory E. Hilmas Jul 2022

Room-Temperature Mechanical Properties Of A High-Entropy Diboride, Alec C. Murchie, Jeremy Lee Watts, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

The mechanical properties of a (Hf,Mo,Nb,Ta,W,Zr)B2 high-entropy ceramic were measured at room temperature. A two-step synthesis process was utilized to produce the (Hf,Mo,Nb,Ta,W,Zr)B2 ceramics. The process consisted of a boro/carbothermal reduction reaction followed by solid solution formation and densification through spark plasma sintering. Nominally, phase pure (Hf,Mo,Nb,Ta,W,Zr)B2 was sintered to near full density (8.98 g/cm3) at 2000°C. The mean grain size was 6 ± 2 µm with a maximum grain size of 17 µm. Flexural strength was 528 ± 53 MPa, Young's modulus was 520 ± 12 GPa, fracture toughness was 3.9 ± 1.2 MPa·m1/2, and hardness (HV0.2) was 33.1 …