Microstructure and mechanical properties of Ni and Ta doped TiB2

0450458 - ÚFM 2016 RIV ES eng A - Abstrakt
Chlup, Zdeněk - Bača, L. - Halasová, Martina - Neubauer, E. - Hadraba, Hynek - Stelzer, N. - Dlouhý, Ivo
Microstructure and mechanical properties of Ni and Ta doped TiB2.
14th International Conference European Ceramics Society. Toledo: ECERS, 2015. ISBN 978-84-606-9257-7.
[ECERS 14 - International Conference of the European Ceramic Society /14./. 21.06.2015-25.06.2015, Toledo]
Grant CEP: GA MŠMT(CZ) ED1.1.00/02.0068
Institucionální podpora: RVO:68081723
Klíčová slova: microstructure * mechanical properties * titanium diboride
Kód oboru RIV: JL - Únava materiálu a lomová mechanika

The effect of metallic dop ants on the microstructure and mechanical properties of titanium diboride (TiB 2 ) were studied. As a dopants Ni and Ta was selected based on the theoretical calculations. Two methods for consolidation were applied the standard and the rapid hot - pressing. Th e sintering process was significantly affected by the addition of metallic dopants. The final densification of prepared composite materials strongly depends on both the amount and presence of individual dopants in the powder mixture. The microstructure was refined when tantalum was present; however, the only tantalum addition did not bring enhanced mechanical properties. The positive influence of both dopants on the microstructure and fracture behaviour was demonstrated by means of assessing the microstruct ure and mechanical properties and fractographic analysis. The effect of zirconia particles originating in the processing route on the microstructure and properties is discussed. This new approach, where the careful selection of metallic dopants is needed, led to the refinement of the microstructure, resulting in an increase of the flexural strength above the level of 700 MPa and the fracture toughness to 6.0 MPa.m 1/2 . It was demonstrated that application of lower sintering temperature is possible when rapid hot pressing method is used.
Trvalý link: http://hdl.handle.net/11104/0252773