Effect of Temperature on the Cyclic Stress Components of Gamma – TiAl Based Alloy with Niobium Alloying

0435835 - ÚFM 2015 RIV CH eng C - Conference Paper (international conference)
Petrenec, Martin - Buček, Petr - Kruml, Tomáš - Polák, Jaroslav
Effect of Temperature on the Cyclic Stress Components of Gamma – TiAl Based Alloy with Niobium Alloying.
Materials Structure & Micromechanics of Fracture VI. Zurich: Trans Tech Publications, 2011 - (Šandera, P.), s. 447-450. Key Engineering Materials, 465. ISBN 978-3-03785-006-0. ISSN 1013-9826.
[MSMF /6./ Materials Structure and Micromechanics of Fracture. Brno (CZ), 28.06.2010-30.06.2010]
R&D Projects: GA ČR GA106/08/1631
Institutional research plan: CEZ:AV0Z20410507
Keywords : Low cycle fatigue * lamellar TiAl alloys * Hysteresis loop * Effective and internal stresses
Subject RIV: JL - Materials Fatigue, Friction Mechanics

Cyclic strain controlled multiple step tests have been performed on cylindrical specimens of cast γ-TiAl based alloy with 2 at.% of Nb with nearly lamellar microstructure at 23 and 750 °C in laboratory atmosphere with the aim to study the effect of temperature on the internal and effective cyclic stress components. At these temperatures, the evolution of the effective and internal stress components and the effective elastic moduli were derived from the hysteresis loops analyzed according to the statistical theory of hysteresis loop. Cyclic hardening/softening curves and cyclic stress-strain curves were obtained at both temperatures. Cyclic stress–strain curves measured using short-cut procedure coincide with the basic cyclic stress-strain curve. They are shifted to lower stresses with increasing temperature. Cyclic stress-strain response at both temperatures was compared and discussed in relation to changes of internal and effective stress components and dislocation modes referred in literature concerning this class of the material.
Permanent Link: http://hdl.handle.net/11104/0239709