Abstract
Isothermal axial strain controlled creep-fatigue tests of a eutectic alloy Sn-37Pb were carried out at room temperature. Four kinds of triangular strain waveform, so called fast-fast, fast-slow, slow-fast and slow-slow, were used. First, constant amplitude fully reversed creep-fatigue tests were done in order to obtain the creep-fatigue properties of the material as the partitioned inelastic strain range versus life relationships, that is, Δε_<ij>-N_<ij> relationships (ij=pp, pc, cp and cc). The obtained Δε_<ij>-N_<ij> relationships were compared with the literature data. Second, two-step variable amplitude fully reversed creep-fatigue tests, so called low-high and high-low, were conducted under fast-fast and slow-fast straining conditions. The results were analyzed and discussed based on the creep-fatigue damage rule proposed by the author and his colleague in the previous work for other high temperature materials. Finally, the effects of ratcheting strain on creep-fatigue life were studied by conducting creep-fatigue tests under the strain waveforms accompanying a small tensile ratcheting strain.
