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

According to resonant vibration fatigue tests, near-eutectic and Pb-rich hy poeutectic Pb-Sn specimens have higher crack-propagation resistance. The te nsile flow stress of Pb-Sn solders that are near eutectic composition incre ases with decreasing Pb content. The solders were tested after either stabi lizing at 373 K or natural aging for 20 days, which gave similar results. T he naturally aged specimens show that the crack-propagation resistance incr eases 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.