Evolution of High Strain Rate Mechanical Properties of SAC-R with High Temperature Storage at 50°C with High and Low Operating-Temperatures

摘要

Previous published literature on material constitutive behavior for SAC-R lead-free solder alloys is restricted to either low strain-rates or room temperature storage (25°C). For the material (SAC-R), high strain-rate data is not available for the storage at high or low operating temperatures. In this experiment, SAC-R has been tested and analyzed at various surrounding temperatures starting from 25°C up to 200°C, with high strain-rates and high aging-temperature as well as low surrounding temperatures from 0°C to -65°C. Storage times of 30-days and 60 days have been studies for a storage temperature of 50°C. Multiple replicates have been tested at each of the conditions and averaged curves reported in the paper. Stress-strain curves have been plotted for a wide range of strain rates and operating temperatures for pristine specimen to aged specimen which have been made using reflow profiles representative of solder-joint production assemblies. The experimental data has been fit into the Anand Viscoplasticity model for (SAC-R) and the Anand constants have been computed by forecasting the measured stress-strain behavior for large ranges of operating temperatures and strain rates. Predictions are compared with the experimentally measured values.