STRAIN-RATE AND TEMPERATURE-DEPENDENT STRESS-STRAIN CURVES OF SN-PB EUTECTIC ALLOY

Tensile tests on cast Sn-Pb eutectic alloy have been carried out at 25, 100, 140, 170-degrees-C and several strain rates ranging from 7 x 10(-3)-7 x 10(-5) s-1. The stress-strain curves obtained were strongly dependent on strain rate and temperature. Under the conditions tested, higher strain-rates gave a higher stress strain curve and a larger strain at fracture. The tensile strength may be expressed by a power function of strain rate whose exponent and coefficient are governed by a kind of Arrhenius' equation. The nominal stress-strain curves showed significant work softening due to diffuse necking; however, the true stress strain curve exhibited slight work softening. Thus the elastic perfectly viscoplastic model can be applied to the solder.