Energy approach to the fatigue of 60/40 solder: Part I - 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 with 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 plastic strain, and not 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 cycling.