Effect of bismuth on the isothermal fatigue properties of Sn-3.5mass%Ag solder alloy

摘要: Sn-3.5mass%Ag eutectic solder is selected as a candidate base alloy for replacing the Sn-Pb, and effect of bismuth (2, 5, 10mass%) on fatigue life bulk at room temperature has been studied over total strain range from 0.3 to 3 percent in tension-tension mode. Fatigue defined number cycles which load decreases half initial value. The dramatically with increasing contents adding this element 2% makes shorter than that tin-lead alloy. Tensile strength significantly increases an increase due solid solution hardening (<5%Bi) or dispersion strengthning fine particles, while ductility system contents. these alloys depends obtained by tensile test. Bi containing Sn-3.5%Ag can be described by, (Δep/2D)·N f 0.59 =0.66 where Nf one-half reduction, Δep plastic cycles, D measured reduction area.