Mechanisms of high temperature damage in elastoplastic cyclic loading of nickel superalloys and TiAl intermetallics

0435829 - ÚFM 2015 RIV NL eng C - Conference Paper (international conference)
Polák, Jaroslav - Obrtlík, Karel - Petrenec, Martin - Man, Jiří - Kruml, Tomáš
Mechanisms of high temperature damage in elastoplastic cyclic loading of nickel superalloys and TiAl intermetallics.
6TH INTERNATIONAL CONFERENCE ON CREEP, FATIGUE AND CREEP-FATIGUE INTERACTION. Amsterdam: Elsevier, 2013 - (Chetal, C.; Jayakumar, T.; Sandhya, R.; Laha, K.; Mathew, M.), s. 114-122. Procedia Engineering, 55. ISSN 1877-7058.
[International Conference on Creep, Fatigue and Creep-Fatigue Interaction /6./. Mamallapuram (IN), 22.01.2012-25.01.2012]
R&D Projects: GA ČR(CZ) GAP107/11/0704; GA ČR(CZ) GAP107/11/2065; GA ČR(CZ) GAP204/11/1453
Institutional support: RVO:68081723
Keywords : fatigue damage * crack initiation * high temperature * nickel superalloy * TiAl intermetallics
Subject RIV: JL - Materials Fatigue, Friction Mechanics

The mechanisms of the fatigue damage in nickel superalloys and TiAl intermetallics used for the design of components working at elevated temperatures are studied. The characteristic surface relief and the accompanying internal dislocation structures of these materials subjected to strain controlled cycling are documented using high resolution SEM, AFM and TEM. Typical structures corresponding to cyclic strain localization are shown in each class of materials and they are discussed in relation to the characteristic internal structure of a particular material and the types of dislocations participating in cyclic plastic deformation. The relation between surface persistent slip markings (extrusions and intrusions) and persistent slip bands in the interior of the material is presented. The mechanisms leading to fatigue crack initiation and early crystallographic crack growth are discussed.
Permanent Link: http://hdl.handle.net/11104/0239705