Crack Initiation and Propagation Evaluation for Sn-5Sb Solder Under Low-Cycle Fatigue

In this study, a crack initiation and propagation behavior of Sn-5Sb lead-free solder under low-cycle fatigue is discussed. Cyclic push-pull loading tests with a single-hole specimen have been conducted at 313 K to investigate the crack initiation and propagation behavior of Sn-5Sb solder which has a higher melting point temperature than that of SnAg-Cu solders. A fatigue life ratio correlates with the crack length within a small scatter. Crack initiates at the early stage, and almost all the life period is crack propagation process independent of strain range and strain rate. The crack propagation rate depends on the strain range and the strain rate. The adaptation of J-integral value for Sn-5Sb solder is also discussed. J-integral value is a suitable parameter for crack propagation rate evaluation.