**7. Conclusion**

This chapter starts with the importance of intermetallic systems in lead-free solders. The effect of some rare earths like lanthanum and indium on intermetallic formation in lead-free alloys has been explained. Tin-zinc-lanthanum and tin-zincaluminium-indium have been chosen for detailed analysis. Microhardness surveys have been done along two perpendicular diagonals of a square-shaped specimen, and the results of the microhardness surveys have been analysed. Microstructures in both these systems have been discussed with respect to the phases present and their distribution. Based upon both the microhardness and microstructure of the two alloys chosen, the presence of intermetallics and the types of intermetallics has been discussed. Growth kinetics of intermetallics has been briefly analysed. SEM fractographs have been taken to show the type of fracture. EDAX has been employed to show the distribution of phases.

*Lead Free Solders*
