Microstructural changes of titanium diboride by addition of Ta and Ni dopants

0474196 - ÚFM 2018 RIV CZ eng A - Abstrakt
Halasová, Martina - Bača, L. - Chlup, Zdeněk - Roupcová, Pavla
Microstructural changes of titanium diboride by addition of Ta and Ni dopants.
CEITEC PhD Retreat: Book of Abstracts. Brno: Masaryk University, 2015 - (Obrusník, A.; Fojtů, M.; Pejović, J.; Hudcová, K.; Sieberová, M.). s. 94-94. ISBN 978-80-210-7825-3.
[CEITEC PhD Retreat. 23.04.2015-24.04.2015, Valtice]
Grant CEP: GA ČR GA14-11234S; GA MŠMT(CZ) ED1.1.00/02.0068
Institucionální podpora: RVO:68081723
Klíčová slova: ceramics * microstructure * titanium diboride
Obor OECD: Ceramics
https://www.ceitec.eu/phd-retreat-abstracts/f33075

Materials predetermined for high temperature applications are usually
based on the ceramics which possess extremely low fracture resistance due
to an inherent brittleness. The possible way how to change this limitation can be
optimisation of the microstructure, i.e., grain arrangement and inter-grain bonding
as is successfully used in silicon nitride. The weak point in such materials is usually
lower temperature resistance of the phase forming inter-grain interface, therefore
the application of silicon nitride is limited to the temperatures around 1000°C.
On the contrary, titanium diboride can serve up to 2000°C and the limitation
is in processing side where solid state sintering is demanding and requires higher
sintering temperatures leading in extreme grain growth. In addition, when liquid
phase sintering is applied the high temperature properties are limited by this
phase. The aim of this work was to describe in detail microstructural development
when combination of used dopants can form high temperature resistant solid
solution. Microstructural changes of pure titanium diboride doped by various
amounts of nickel and tantalum were investigated using ceramographic methods
supplemented by elemental SEM microanalysis and X-ray analysis. Materials
used in this study were prepared by the standard and the rapid hot-pressing
method at temperatures around 2000°C. The effect of processing route applied
as well as the effect of selected metallic elements was studied from the grain
growth and a porosity development point of view. The link between resulting
microstructure and basic mechanical properties was found and positive influence
of dopants was determined.

Trvalý link: http://hdl.handle.net/11104/0276489