Surface relief evolution in IN792-5A nickel superalloy under high temperature fatigue straining with hold times

0435156 - ÚFM 2015 RIV CH eng C - Konferenční příspěvek (zahraniční konf.)
Šmíd, Miroslav - Obrtlík, Karel
Surface relief evolution in IN792-5A nickel superalloy under high temperature fatigue straining with hold times.
Materials Structure and Micromechanics of Fracture VII. Zurich: Trans Tech Publications, 2014 - (Šandera, P.), s. 429-432. Key Engineering Materials, 592-593. ISBN 978-3-03785-934-6. ISSN 1013-9826.
[MSMF 7 - International Conference on Materials Structure & Micromechanics of Fracture /7./. Brno (CZ), 01.07.2013-03.07.2013]
Grant CEP: GA MPO FR-TI3/055; GA ČR(CZ) GAP107/11/2065; GA MŠMT(CZ) EE2.3.20.0214
Institucionální podpora: RVO:68081723
Klíčová slova: Nickel-base superalloy * Surface relief * Fatigue * Hold times * High temperature fatigue
Kód oboru RIV: JL - Únava materiálu a lomová mechanika

The present paper is focused on scanning electron microscopy investigation of surface relief developed in cyclically strained specimens at high temperature. Symmetrical fatigue tests without hold times and with tensile or compressive hold times were used in strain control regime. The gauge length of specimens was analyzed after cyclic straining in a wide range of total strain amplitudes. Experimental temperature was 800 °C and selected hold time was 10 minutes. Surface relief is developed during the cyclic straining in localized plastic strain areas. Developed surface relief strongly depends on the type of fatigue test and a value of total strain amplitude. Well-developed surface persistent slip markings were observed after cyclic loading without hold times. Another group of observed slip markings with perpendicular orientation to stress axis exhibits irregular and wavy morphology. Similar markings were also observed on specimen surfaces after fatigue tests with tensile hold times as well as compressive hold times. Third group, named imperfect persistent slip markings, was observed after cyclic straining with tensile holds. In some suitably oriented grains, areas with high density of well-developed markings with irregular morphology were found.
Trvalý link: http://hdl.handle.net/11104/0239055