31. On the Comparison of Additive-Free HfBrSiC Ceramics Sintered by Reactive Hot-Pressing and Spark Plasma Sintering

  1. Manuel E. Brito,
  2. Peter Filip,
  3. Charles Lewinsohn,
  4. Ali Sayir,
  5. Mark Opeka and
  6. William M. Mullins
  1. Frederic Monteverde1 and
  2. Alida Bellosi2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291283.ch31

Developments in Advanced Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 8

Developments in Advanced Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 8

How to Cite

Monteverde, F. and Bellosi, A. (2005) On the Comparison of Additive-Free HfBrSiC Ceramics Sintered by Reactive Hot-Pressing and Spark Plasma Sintering, in Developments in Advanced Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 8 (eds M. E. Brito, P. Filip, C. Lewinsohn, A. Sayir, M. Opeka and W. M. Mullins), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291283.ch31

Author Information

  1. 1

    National Research Council—Institute of Science and Technology for Ceramics Via Granarolo 64 48018 Faenza- Italy

  2. 2

    National Research Council—Institute of Science and Technology for Ceramics Via Granarolo 64 48018 Faenza-Italy

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9781574982619

Online ISBN: 9780470291283

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Keywords:

  • temperature;
  • microstructure;
  • diborides;
  • atmosphere;
  • synthesis

Summary

Ultra-high-temperature HfB2-SiC ceramics were produced by reactive hot-pressing (RHP) and spark plasma sintering (SPS) successfully. In the former case, a mixture of Hf/Si/B4C, mechanically mixed in molar ratio 2.2/0.8/1, was “in-situ” converted into HfB2 and SiC, and then directly hot-pressed until full density was achieved. In the SPS case, a powder mixture of HfB2 + 30vol% SiC was fully densified at 2,100°C, 100°C/min heating rate and 2 min dwell time. The microstmcture in both the materials consisted of faceted diboride grains, finer in the RHP case, with SiC particles evenly distributed intergranularly. The combination of some thermo-mechanical properties was of considerable significance. Flexural strength of the RHP fabricated material measured at 25 °C and 1,500 °C in ambient air was 770 ± 35 and 310 ± 15 MPa, respectively. A relevant merit characterized fracture toughness and flexural strength of the material produced by SPS: the values measured at room temperature (3.9 ± 0.3 MPa√m and 590 ± 50 MPa, respectively) did not decrease appreciably at 1500 °C (4.0 ± 0.1 MPa√m and 600 ± 15 MPa, respectively).