Effect of strain rate and temperature on tensile flow behavior of SnAgCu nanocomposite solders

The tensile flow behavior of Sn-3.8Ag-0.7Cu (SAC387) nanocomposite solders have been studied with strain rates ranging from 10-5 to 10-1 s-1 and at temperature of 25, 75 and 125°C. The flow stress and the Hollomon parameters were observed to increase substantially with increasing strain rate. The strain hardening exponent increased substantially with increasing strain rate and decreasing with temperature for all the composite solders investigated. The strain rate dependence of strain hardening exponent was stronger at higher temperatures for SAC387 solder alloy, while it is weaker for composite solders reinforced with nano sized Mo particles. The strain hardening exponent was found to be less sensitive to temperature at higher strain rates. The fractographic features of ambient and elevated temperature tensile fracture surfaces of the nanocomposite solders deformed at various strain rates are discussed.