Microstructure degradation in high temperature fatigue of TiAl

0428526 - ÚFM 2015 RIV GB eng J - Článek v odborném periodiku
Kruml, Tomáš - Obrtlík, Karel
Microstructure degradation in high temperature fatigue of TiAl.
International Journal of Fatigue. Roč. 65, AUG (2014), s. 28-32. ISSN 0142-1123. E-ISSN 1879-3452
Grant CEP: GA ČR(CZ) GAP107/11/0704
Institucionální podpora: RVO:68081723
Klíčová slova: Low cycle fatigue * lamellar TiAl alloy * high temperature fatigue * dislocations
Kód oboru RIV: JL - Únava materiálu a lomová mechanika
Impakt faktor: 2.275, rok: 2014

Low cycle fatigue properties of lamellar TiAl with 8 at.% Nb were studied at four temperatures: room temperature, 700, 750 and 800 °C. Up to 750 °C, stable cyclic behaviour is observed while cyclic softening is characteristic for 800°C. The strength of the alloy is still high even at 800 °C. The TEM observation did not reveal any substantial changes in the microstructure due to the cycling at RT. At 750 °C, the lamellar structure was in some places destroyed by cyclic plastic straining and pure -phase islands with high density of dislocation debris were formed. At 800 °C, the domains without lamellar structure cover about 10% of volume and are almost dislocation free. The destruction of lamellar microstructure and possible annealing of dislocation debris is the reason for marked cyclic softening at 800 °C.
Trvalý link: http://hdl.handle.net/11104/0233888