Effect of lead content on vibration fracture behavior of Pb–Sn eutectic solder

According to resonant vibration fatigue tests, near-eutectic and Pb-rich hypoeutectic Pb–Sn specimens have higher crack-propagation resistance. The tensile flow stress of Pb–Sn solders that are near eutectic composition increases with decreasing Pb content. The solders were tested after either stabilizing at 373 K or natural aging for 20 days, which gave similar results. The naturally aged specimens show that the crack-propagation resistance increases with increasing aging time. A striated deformation was found to occur in Sn grain of the lower Pb specimen. This phenomenon is correlated with a deterioration of crack-propagation resistance.