9215694 Zamrik A series of multiaxial thermal-mechanical fatigue (TMF) tests are to be conducted using two structural materials: type 316 stainless steel and Nickel-base superalloy Waspaloy. The TMF tests will be conducted in continuous cycling modes and with holds-in- strain/temperature imposed on the continuous cycling waveforms. The hold-periods are imposed in the TMF loading cycles to induce time dependent effects such as creep and oxidation. The objective of this research is to characterize the mechanical and micromechanical TMF responses of these two materials under multiaxial isothermal fatigue and creep-fatigue responses of these two structural materials from available data. Extensive microstructural evaluations of the fracture and failure processes of these two materials will be conducted in order to develop a physical-based universal life prediction concept. A universal multiaxial fatigue life prediction concept developed for the isothermal case will be applied to the multiaxial TMF data obtained in this research study. ***
