Rare-earth element doped Si3N4/SiC micro/nano-composites-RT and HT mechanical properties

0345837 - ÚFM 2011 RIV GB eng J - Článek v odborném periodiku
Lojanová, Š. - Tatarko, P. - Chlup, Zdeněk - Hnatko, M. - Dusza, J. - Lenčéš, Z. - Šajgalík, P.
Rare-earth element doped Si3N4/SiC micro/nano-composites-RT and HT mechanical properties.
Journal of the European Ceramic Society. Roč. 30, č. 9 (2010), s. 1931-1944. ISSN 0955-2219. E-ISSN 1873-619X
Výzkumný záměr: CEZ:AV0Z20410507
Klíčová slova: Si3N4 * SiC * Nano-composites * Fracture toughness * Hardness * Strength * Creep
Kód oboru RIV: JH - Keramika, žáruvzdorné materiály a skla
Impakt faktor: 2.574, rok: 2010

Dense Si3N4/SiC micro/nano-composites with varying grain boundary phase composition were fabricated by hot-pressing under the same conditions. Six different sintering aids (Lu2O3, Yb2O3, Y2O3, Sm2O3, Nd2O3 and La2O3) were used. The formation of SiC nano-inclusions was achieved by in situ carbothermal reduction of SiO2 by C during the sintering process. Room temperature, fracture toughness, hardness and strength tended to increase when the cation radius of the rare-earth element used in the oxide additive decreased (i.e. from La3+ to Lu3+). The composite material with Lu2O3 sintering additive showed the highest hardness and had reasonably high fracture toughness and strength. The same micro/nano-composite also possessed the highest creep resistance in the temperature range from 1250 ◦C to 1400 ◦C and with loads in the range 50–150MPa.
Trvalý link: http://hdl.handle.net/11104/0187022