Fatigue Life and Its Estimation for Pb/Sn Solder Alloy

摘要

In this paper, we propose a method for prediction of number of cycle to fatigue failure of Pb/Sn solder alloyrnsubjected to cyclic tension-compression loading. Cyclic tension-compression loadings are conducted under severalrnloading conditions, such as constant strain amplitudes under constant strain rates at several temperatures, andrnconstant strain amplitudes with changing strain rate during the loading. Based on the tests, we show that thernrelationship between number of cycle to fatigue failure of 60Sn-40Pb solder alloys and the inelastic work densityrnper unit time, which is expressed by a formula irrespective of the strain amplitude, strain rate and temperature. Wernalso construct the constitutive model for cyclic viscoplasticity which can calculate the inelastic work density perrnunit time under arbitrary loading condition. As a result, number of cycle to fatigue failure can be successfullyrnpredicted by the formula with the inelastic work density per unit time calculated by the constitutive model.