Nanoscale Mechanical Properties of Intermetallics in Lead-Free Systems

Bimetallic couples formed between commercially available lead-free alloys and selected contact materials were subjected to diffusion annealing using thermal gradients. Following diffusion annealing and aging, the contact interfaces were subjected to a detailed metallographic, scanning electron microscope (SEM), and energy dispersive X-ray (EDX) analyses. In addition, electrical resistance was used for electrical characterization of the intermetallics formed at the contact interfaces, whereas the nanoindentation technique was used to determine the nanoscale mechanical properties. An attempt was made to correlate the observed nanoindentation data with the microstructures of the intermetallic phases formed and electrical resistivity.