Fatigue life and fracture of cast gamma TiAl intermetallic alloy at room and elevated temperatures

0439947 - ÚFM 2015 RIV CZ eng C - Conference Paper (international conference)
Petrenec, Martin - Šmíd, Miroslav - Polák, Jaroslav
Fatigue life and fracture of cast gamma TiAl intermetallic alloy at room and elevated temperatures.
METAL 2011 Conference Proceedings - Papers. Ostrava: Tanger s.r.o., 2011, s. 969-974. ISBN 978-80-87294-24-6.
[METAL 2011 /20./. Brno (CZ), 18.05.2011-20.05.2011]
R&D Projects: GA ČR(CZ) GAP107/11/0704
Institutional research plan: CEZ:AV0Z20410507
Keywords : low cycle fatigue * cast gamma TiAl alloy * fracture surfaces * PSMs * elevated temperature
Subject RIV: JL - Materials Fatigue, Friction Mechanics

The low-cycle fatigue properties, surface relief and fracture surfaces of cast TiAl alloys with 2 at.% Nb having nearly lamellar microstructure were studied at room temperature and at 750 degrees C. Cyclic stress-strain curves (CSSC) and fatigue life curves were obtained at both temperatures. The surface relief and the fracture surfaces of fractured specimens were observed using scanning electron microscopy. At room temperature, significant cyclic hardening is observed whereas at 750 degrees C cyclic response was stable. Parameters of the CSSC, the Manson-Coffin law and the Basquin law were determined. Persistent slip markings formed along interlamellar interfaces were predominant locations for fatigue cracks at both temperatures. The cracks initiated at surface or in sub-surface region led to the formation of smooth flat areas on the fracture surface corresponding to the persistent slip bands.
Permanent Link: http://hdl.handle.net/11104/0243315