Abstract
The fatigue limit of metal is dicided by 10^7 cycles fatigue test, and it takes long time and costs. Recently, fatigue limit estimation based on energy dissipation has been attracting. In this method, temperture change due to irreversible energy dissipation is measured by the infrared thermography for various levels of stress amplitude. In this study, this method was applied to extruded AZ31B magnesium alloy. It was found that harmonic vibration stress from fatigue testing machine affects the measurement of dissipated energy. This effect can be suppressed by adjustment of fatigue testing machine. New estimation scheme which is based on the incresing rate of dissipated energy was applied. The estimated fatigue limit obtained by the new estimation scheme coinceies with the compressive yield stress.
