Crack Resistance Characterization in TiAl Intermetallics with Enhanced Toughness

0480944 - ÚFM 2018 RIV CH eng C - Conference Paper (international conference)
Dlouhý, Ivo - Stratil, Luděk - Fukutomi, H. - Hasegawa, M.
Crack Resistance Characterization in TiAl Intermetallics with Enhanced Toughness.
Analysis of Damage Features and Failures for Structural Materials and Parts. Zürich: Trans Tech Publications Ltd, 2017 - (Strnadel, B.), s. 13-18. Key Engineering Materials, 741. ISBN 978-3-0357-1127-1. ISSN 1013-9826.
[2016 - International Workshop on New Methods of Damage and Failure Analysis of Structural Parts /7./. Yokohama (JP), 01.11.2016-04.11.2016]
Institutional support: RVO:68081723
Keywords : Titanium aluminides * Intermetallics * Fracture micromechanisms * Shear ligament toughening * Fracture toughness * Crack resistance
OECD category: Materials engineering

The paper is focused on the analysis of the role of lamellar microstructure in fracture performance of model TiAl intermetallic compound. Coarse lamellar colonies and, at the same time, fine lamellar morphology were prepared by compressive deformation at 1553 K (region of stable alpha phase in TiAl equilibrium diagram) followed by controlled cooling to 1473 K (region of alpha+gamma phase) with delay on this temperature and then cooling down. The fracture toughness was evaluated by means of chevron notch technique. In addition, because of enhanced toughness, crack resistance curves were obtained by load - unload technique of pre-racked beams, namely in two directions of crack propagation relative to lamellar structure. Extensive development of shear ligament toughening mechanism was observed in fracture surfaces leading to quite good fracture toughness thanks to the heat treatment applied.
Permanent Link: http://hdl.handle.net/11104/0276617