Effect of metallic dopants on the microstructure and mechanical properties of TiB2

0450347 - ÚFM 2016 RIV GB eng J - Journal Article
Chlup, Zdeněk - Bača, L. - Halasová, Martina - Neubauer, E. - Hadraba, Hynek - Stelzer, N. - Roupcová, Pavla
Effect of metallic dopants on the microstructure and mechanical properties of TiB2.
Journal of the European Ceramic Society. Roč. 35, č. 10 (2015), s. 2745-2754. ISSN 0955-2219. E-ISSN 1873-619X
R&D Projects: GA ČR(CZ) GAP108/11/1644; GA MŠMT(CZ) ED1.1.00/02.0068
Grant - others:The Austrian Research Promotion Agency (FFG)(AT) 834287
Institutional support: RVO:68081723
Keywords : Titanium diboride * Metallic dopants * Microstructure * Mechanical properties * Fracture behaviour1
Subject RIV: JL - Materials Fatigue, Friction Mechanics
Impact factor: 2.933, year: 2015

2015AbstractTitanium diboride (TiB2) doped with Ni and Ta was prepared by both the standard and the rapid hot-pressing method. The obvious limitations ofthe pure TiB2ceramics to be fully densified are the low inter-diffusion rates, exaggerated grain growth at temperatures exceeding 2000◦C, andmicro-cracks produced after sintering causing high brittleness. There is only limited number of approaches how to improve the fracture resistancetogether with sinterability. The method used in this work is based on doping of the basic microstructure by nickel and tantalum metals with the aimto prepare composite systems with high density and enhanced fracture resistance. The positive influence of both dopants on the microstructure andfracture behaviour was demonstrated by means of microstructure, mechanical properties and fractographic analysis. This new approach, where thecareful selection of metallic dopants is needed, led to the refinement of microstructure resulting in the increase of flexural strength above the levelof 700 MPa and fracture toughness of 6.0 MPa m1/2.
Permanent Link: http://hdl.handle.net/11104/0251716