ENERGY APPROACH TO THE FATIGUE OF 60 40 SOLDER .1. INFLUENCE OF TEMPERATURE AND CYCLE FREQUENCY/

This study correlates previously published fatigue life data with the hysteresis energy, and compares this to the previous correlation's wit h the applied plastic strain. It was found that, while the hysteresis energy could be used to describe the fatigue life, corrections must be made to account for the temperature and strain rate dependence of the flow stress. Because of these factors, it is believed that the plasti c strain, and plot the hysteresis energy, is the true governing factor in determining the fatigue life. Part I (described here) covers only the influence of temperature and cycle frequency for symmetric cycling . Part II, to be published, will deal with hold time and asymmetric cy cling.