Interaction of fatigue and creep in MAR-M 247 superalloy

• DOI: 10.1016/j.prostr.2020.01.086
• Publication Date: 2020-02-19T12:55:41Z
• Authors: Vít Horník; Stanislava Fintová; Miroslav Šmíd; Pavel Hutař; Karel Hrbáček; Ludvík Kunz
• Keywords: MAR-M 247; high temperature; creep/fatigue interaction; superalloy; 0203 mechanical engineering; 02 engineering and technology

Abstract Lifetime of MAR-M 247 Ni-based superalloy was experimentally studied under high-frequency cyclic loading (120 Hz) with constant tensile mean stress σm = 300 MPa at temperature 900 °C in air. The stress amplitude σa was changed in order to investigate the superalloy lifetime in a wide range of conditions, from pure creep to pure fatigue. The superposition of the stress amplitude on the mean stress does not influence the specimen lifetime until a threshold value is reached. Scanning electron microscopy was utilized for the fracture surface observation with the aim to identify the governing damage mechanisms for particular test conditions.