Damage evolution governed by microcrack nucleation with application to the fatigue of 63Sn--37Pb solder

摘要

In many materials, including tin--lead eutectic solder, a substantial portion of their fatigue life is spent in accumulation of randomly distributed microcracks. An assembly of discrete interconnected elements (e.g. grains or phases) approximates the solid in this paper. Percolation theory is employed to derive critical microcrack density and to predict size effect. Self similarity in microcrack nucleation leads to a simple power law for lifetime prediction. Its application to the fatigue of tin--lead eutectic solder shows a good agreement with experimental data.