Low-temperature consolidation of high-strength TiB2 ceramic composites via grain-boundary engineering using Ni-W alloy

0494783 - ÚFM 2019 RIV CH eng J - Journal Article
Chlup, Zdeněk - Bača, L. - Hadraba, Hynek - Kuběna, Ivo - Roupcová, Pavla - Kováčová, Z.
Low-temperature consolidation of high-strength TiB2 ceramic composites via grain-boundary engineering using Ni-W alloy.
Materials Science and Engineering A Structural Materials Properties Microstructure and Processing. Roč. 738, DEC (2018), s. 194-202. ISSN 0921-5093. E-ISSN 1873-4936
R&D Projects: GA MŠMT(CZ) LQ1601
Institutional support: RVO:68081723
Keywords : Titanium diboride * Metallic dopants * Microstructure * Mechanical properties * Fracture behaviour
OECD category: Ceramics
Impact factor: 4.081, year: 2018

The concept of the consolidation of titanium diboride at relatively low temperature via formation of the solid
solution was used in this research. A specially designed Ni-W alloy prepared by mechanical alloying method was
used as the solid solution formation additive. The low amount of Ni-W alloy and TiB2 powder were mixed
together and consequently consolidated in the temperature interval from 1300 °C to 1400 °C. The development
of the microstructure and resulting mechanical behaviour of these composites were analysed in detail. The grain
size of TiB2 below 3 micrometres was obtained for all processing temperatures. The highest processing temperature
of 1400 °C resulted in the flexural strength on the level of 875 MPa and the elastic modulus being nearly
500 GPa. The fracture toughness was about 5 MPam0.5. Formation of the solid solution was confirmed by XRD
and TEM analysis. Due to the targeted change in chemical composition on grain boundaries and TiB2 lattice
distortions by addition of transition metals with higher ionic radii a hypothesis about the preferential formation
of solid solution layer on the surface of TiB2 grains taking into account their orientation was formulated.
Permanent Link: http://hdl.handle.net/11104/0289472