High and Low Temperature Strain-Life Behavior of a Pb Rich Solder

Abstract

This paper describes the fatigue behavior of a Pb rich solder, 92.5Pb, 2.5Ag, 5.0Sn (Indalloy 151), tested at −50°C and +150°C. The results are compared to previously reported studies of 60Sn/40Pb solder and to tests of Indalloy 151 performed at 35° C. The Coffin-Manson exponent is larger at all temperatures for the Indalloy 151 compared to the 60Sn/40Pb, but this effect is especially pronounced at +150° C where the exponent is 0.85 for the Indalloy 151 and only 0.35 for the 60Sn/40Pb. This gives rise to a crossover in the behavior of the two solders with the Indalloy 151 exhibiting a longer fatigue life at high strains and the 60Sn/40Pb exhibiting superior behavior at low strains.