Experiences in the determination of TMF, LCF and creep life of CMSX-4 in four-point bending experiments

The thermo-mechanical fatigue (TMF), low cycle fatigue (LCF) and creep life of rectangular flat specimen were evaluated by means of four-point bending tests. Experiments were performed on the single crystal superalloy CMSX-4 mainly in the orientation (00 1), but also orientations (0 1 1) and (1 1 1). While the TMF-Tests were performed in the temperature ranges from 250 to 750 degrees C, 450-950 degrees C and 550-1050 degrees C with a heating rate of 25 degrees C/s and a cooling rate of 12.5 degrees C/s, the LCF and creep tests were performed at 750, 950 and 1050 degrees C. Two different bending devices were designed and machined for the creep test and the LCF and TMF test respectively. In this work the experiences with the design and performance of the experimental test setup of the LCF and TMF experiments, especially with temperature and strain control are reported. Results and theoretical interpretation are given in [Xu J, Reuter S, Rothkegel W. Tensile and bending thermo-mechanical fatigue testing on cylindrical and flat specimens of CMSX-4 for design of future high-pressure turbine blades, TMF-Workshop, 22-23 September, Berlin; 2005.]. (C) 2007 Elsevier Ltd. All rights reserved.